diff --git a/backend/api/v1/modules/a76/audit_log/services/service.py b/backend/api/v1/modules/a76/audit_log/services/service.py
index 10ca1f55..368e3fed 100644
--- a/backend/api/v1/modules/a76/audit_log/services/service.py
+++ b/backend/api/v1/modules/a76/audit_log/services/service.py
@@ -103,8 +103,7 @@ class AuditService:
         )
         
         db.add(log)
-        db.commit()
-        db.refresh(log)
+        db.flush()
         return log
 
     @staticmethod
diff --git a/backend/api/v1/modules/a76/invoices/common/common_validators.py b/backend/api/v1/modules/a76/invoices/common/common_validators.py
index f4c0db4c..fac17226 100644
--- a/backend/api/v1/modules/a76/invoices/common/common_validators.py
+++ b/backend/api/v1/modules/a76/invoices/common/common_validators.py
@@ -68,6 +68,10 @@ def invoice_exists_by_id(
     company_id: int,
     errors: Optional[ErrorCollector],
 ):
+    """
+    Check if an invoice exists by ID. 
+    WARNING: Adds a DUPLICATE error if found (to be used when creating NEW invoices with specific IDs).
+    """
     invoice = (
         db.query(models.InvoiceHeader)
         .filter(
@@ -88,6 +92,41 @@ def invoice_exists_by_id(
         return invoice
     return None
 
+def invoice_id_required(
+    db: Session,
+    invoice_id: int,
+    tenant_id: int,
+    company_id: int,
+    errors: ErrorCollector,
+) -> Optional[models.InvoiceHeader]:
+    """
+    Validates that an invoice exists by ID.
+    Adds a NOT_FOUND error if it doesn't exist.
+    """
+    if not invoice_id:
+        errors.add_required_error(field="invoice_id")
+        return None
+
+    invoice = (
+        db.query(models.InvoiceHeader)
+        .filter(
+            models.InvoiceHeader.id == invoice_id,
+            models.InvoiceHeader.tenant_id == tenant_id,
+            models.InvoiceHeader.company_id == company_id,
+        )
+        .first()
+    )
+
+    if not invoice:
+        errors.add_error(
+            field="invoice_id",
+            message=f"La factura con ID '{invoice_id}' no existe.",
+            solution=["Seleccionar una factura válida."],
+            code="NOT_FOUND",
+            value=str(invoice_id),
+        )
+    return invoice
+
 def invoice_processed(
     db: Session,
     invoice_id: str,
diff --git a/backend/api/v1/modules/a76/invoices/exports/process/main_process.py b/backend/api/v1/modules/a76/invoices/exports/process/main_process.py
index 0ea95e59..f7e283e7 100644
--- a/backend/api/v1/modules/a76/invoices/exports/process/main_process.py
+++ b/backend/api/v1/modules/a76/invoices/exports/process/main_process.py
@@ -1,204 +1,119 @@
-
+import logging
+logger = logging.getLogger(__name__)
+from datetime import datetime
+from decimal import Decimal
 from typing import List
 
 from sqlalchemy.orm import Session
 
-from api.v1.modules.a76.invoices.models import InvoiceHeader
-from api.v1.modules.a76.items.models import LineItem
+from api.v1.modules.a76.invoices.models import InvoiceHeader, InvoiceStatus
+from api.v1.modules.a76.general_catalogs.exchange_rate.models import ExchangeRate
 from core.exceptions import ErrorCollector
 from .pre_validators import pre_validators
-from .sub_process.assign_no_discharges import assign_no_discharges_items, assign_no_discharges_series
-from .sub_process.review_class import review_class
 from .sub_process.review_exchange_rate import review_exchange_rate
 from .sub_process.assign_values import assign_values
-from .sub_process.review_exchange_rate import review_exchange_rate
-from .sub_process.review_qty_vs_weight import review_qty_vs_weight
-from .sub_process.review_unit_cost import review_unit_cost
-from .sub_process.review_limits import limit_weight, limit_value
-from .sub_process.series.review_qty_series import review_qty_series
+from .sub_process.assign_no_discharges import assign_no_discharges_items, assign_no_discharges_series
+
+# Parameter Service
+from api.v1.modules.a76.app_settings.service import AppSettingsService
+
+
+from .sub_process.finalize_invoice import finalize_invoice_no_discharge, finalize_invoice_with_discharge
 from .sub_process.download_balance_collector import collect_lines_to_discharge
-from .sub_process.discharge_types import DownloadEntry
-from .sub_process.finalize_invoice import (
-    finalize_invoice_no_discharge,
-    finalize_invoice_with_discharge,
-)
-from .sub_process.review_origin_procedure import review_origin_procedure
 from .sub_process.fill_available_balances import fill_available_balances
 from .sub_process.compare_balances import compare_balances
 from .sub_process.verify_consolidated import verify_consolidated
-from .sub_process.generate_definitive_import import (
-    generate_definitive_import,
-    generate_definitive_import_all_lines,
-)
 
-# ---------------------------------------------------------------------------
-# Bloque reutilizable: descarga normal (AFIJO / DONAC / SCRAP / REEXP / VEMEX)
-# ---------------------------------------------------------------------------
-
-def _process_with_discharge(
-    db: Session,
-    invoice: InvoiceHeader,
-    lines: List[LineItem],
-    errors: ErrorCollector,
-) -> None:
-    """
-    Secuencia común para los tipos de factura que realizan descarga de saldos:
-    AFIJO, DONAC, SCRAP, REEXP, VEMEX.
-    """
-    assign_no_discharges_series(db, lines, errors)
-    review_class(db, lines, errors)
-    review_exchange_rate(db, invoice, errors)
-    assign_values(db, invoice, lines, invoice.tenant_id, invoice.company_id, errors)
-
-    review_qty_vs_weight(lines, invoice.logistics.weight_type.upper(), errors)
-
-    review_unit_cost(lines, errors)
-    total_qty, total_net_weight = limit_weight(lines)
-    total_value = limit_value(lines)
-    review_qty_series(db, invoice, lines, invoice.tenant_id, invoice.company_id, errors)
-
-    # QUIERE_DESCARGAR → LLENA_QUEUE_SALDOS → COMPARA_SALDOS
-    to_discharge = collect_lines_to_discharge(db, invoice, lines, errors)
-
-    fill_available_balances(db, invoice, to_discharge, errors)
-    compare_balances(db, invoice, to_discharge, errors)
-    verify_consolidated(db, invoice, to_discharge, errors)
-
-    finalize_invoice_with_discharge(db, invoice, lines, errors, to_discharge)
-
-
-# ---------------------------------------------------------------------------
-# Proceso principal
-# ---------------------------------------------------------------------------
-
-def main_process(db: Session, invoice: InvoiceHeader, tenant_id: str, company_id: str) -> dict:
-    """
-    Proceso principal para actualizar facturas de exportación.
-
-    Flujo (porta la rutina principal del legacy SCAII – Facturas de Exportación):
-
-    1. Validaciones previas (pre_validators)
-    2. TODO: Compartir parámetros generales (QSisGen / GEmpresa)
-    3. TODO: Compartir parámetros de exportación (QSisExpo) según EsCambioRegimen
-    4. TODO: Validar permisos de usuario (GUsuarios / GNivelesSeguridad)
-    5. TODO: Iniciar transacción SQL (BEGIN TRAN)
-    6. Verificar que existan partidas
-    7. TODO: Obtener tipo de cambio según SisGen:CalValBaseTCPedExpo
-       (TCPED desde la fecha de pago del pedimento, o TCFAC desde la factura)
-    8. TODO: Validar que la factura no exista ya en Importaciones Definitivas (si GeneraID='S')
-    9. CASE invoice_type → ejecutar sub-proceso específico por tipo:
-       - NODES : sin descarga
-       - AFIJO / DONAC / SCRAP : con descarga + lógica de CambioRegimen opcional
-       - REEXP / VEMEX          : con descarga + revisión de procedencia DEF
-    10. Si hay errores: rollback implícito (raise)
-        Si no hay errores: COMMIT y marcar factura como procesada
-    """
-    errors = ErrorCollector()
-
-    # --- Paso 1: Validaciones previas ----------------------------------------
+def pre_process(db: Session, invoice: InvoiceHeader, tenant_id: str, company_id: str, errors: ErrorCollector) -> list:
+    """Validaciones previas y obtención de partidas."""
     lines = pre_validators(db, invoice, tenant_id, company_id, errors)
-    errors.raise_if_errors()
-
-    # --- Paso 2-4: Parámetros generales, parámetros expo y permisos ----------
-    # TODO: Compartir QSisGen / GEmpresa
-    # TODO: Compartir QSisExpo (EsCambioRegimen = 'S' → SisExp:EsCambioRegimen = 'CR')
-    # TODO: Validar permisos usuario (GUsuarios / GNivelesSeguridad)
-
-    # --- Paso 5: Iniciar transacción -----------------------------------------
-    # TODO: BEGIN TRAN  (en el legacy: GSQLFile{PROP:SQL} = 'BEGIN TRAN')
-
-    # --- Paso 6: Verificar que existan partidas ------------------------------
     if not lines:
-        errors.add_error(
-            field="items",
-            message="Esta Factura no tiene partidas.",
-            solution=["Capturar al menos una partida a la factura."],
-            code="NO_ITEMS_FOUND",
-        )
-        errors.raise_if_errors()
+        errors.add_error(field="line_items", message="La factura debe contener partidas.", solution=["Agregue partidas."], code="NO_LINE_ITEMS")
+    return lines
 
-    # --- Paso 7: Tipo de cambio ----------------------------------------------
-    # TODO: Si SisGen:CalValBaseTCPedExpo = 1:
-    #         invoice.which_exchange_rate = 'TCPED'
-    #         Buscar pedimento (EqiPed:Pedimento = EqiFex:PedimentoExpo)
-    #         Buscar GTipoCambio por EqiPed:Fecha_Pago
-    #         exchange_rate = GenTC:Valor
-    #       Else:
-    #         invoice.which_exchange_rate = 'TCFAC'
-    #         exchange_rate = invoice.financials.exchange_rate
 
-    # --- Paso 8: Validar que la factura no exista en ImportDef ---------------
-    # TODO: Si invoice.generate_id = True:
-    #         Buscar en QFacImpDef por invoice.invoice_number
-    #         Si ya existe → agregar error
-
-    # --- Paso 9: Sub-proceso por tipo de factura -----------------------------
-    invoice_type = invoice.invoice_type
-
-    if invoice_type == "NODES":
-        # Sin descarga de saldos        
-        assign_no_discharges_items(lines, errors)
-        assign_no_discharges_series(db, lines, errors)
-        review_class(db, lines, errors)
-        review_exchange_rate(db, invoice, errors)
-        assign_values(db, invoice, lines, invoice.tenant_id, invoice.company_id, errors)
-
-        review_qty_vs_weight(lines, invoice.logistics.weight_type.upper(), errors)
-
-        review_unit_cost(lines, errors)
-        review_qty_series(db, invoice, lines, tenant_id, company_id, errors)
-        total_qty, total_net_weight = limit_weight(lines)
-        total_value = limit_value(lines)
-        
-        finalize_invoice_no_discharge(db, invoice, lines, errors)
-
-    elif invoice_type == "AFIJO":
-        if invoice.compliance_mx and invoice.compliance_mx.is_regime_change:
-            review_origin_procedure(db, invoice, lines, "TEM", errors)
-            if invoice.generate_id and invoice.generate_desc_parties == "Todas":
-                def_inv = generate_definitive_import(db, invoice, errors)
-                if def_inv:
-                    generate_definitive_import_all_lines(db, invoice, def_inv, errors)
-
-        _process_with_discharge(db, invoice, lines, errors)
-
-    elif invoice_type == "DONAC":
-        _process_with_discharge(db, invoice, lines, errors)
-
-    elif invoice_type == "SCRAP":
-        if invoice.compliance_mx and invoice.compliance_mx.is_regime_change:
-            review_origin_procedure(db, invoice, lines, "TEM", errors)
-            if invoice.generate_id and invoice.generate_desc_parties == "Todas":
-                def_inv = generate_definitive_import(db, invoice, errors)
-                if def_inv:
-                    generate_definitive_import_all_lines(db, invoice, def_inv, errors)
-
-        _process_with_discharge(db, invoice, lines, errors)
-
-    elif invoice_type == "REEXP":
-        review_origin_procedure(db, invoice, lines, "DEF", errors)
-        _process_with_discharge(db, invoice, lines, errors)
-
-    elif invoice_type == "VEMEX":
-        review_origin_procedure(db, invoice, lines, "DEF", errors)
-        _process_with_discharge(db, invoice, lines, errors)
-
-    else:
-        errors.add_error(
-            field="invoice_type",
-            message=f"{invoice_type} no es un Tipo de Factura válido, llamar al proveedor del Sistema SCAII.",
-            solution=["Verificar el tipo de factura de exportación."],
-            code="INVALID_INVOICE_TYPE",
-            value=invoice_type,
-        )
-
-    # --- Paso 10: Commit / Rollback ------------------------------------------
+def main_process(db: Session, invoice: InvoiceHeader, tenant_id: str, company_id: str, username: str = "SYSTEM") -> dict:
+    """Proceso principal para facturas de exportación."""
+    errors = ErrorCollector()
+    lines = pre_process(db, invoice, tenant_id, company_id, errors)
     errors.raise_if_errors()
 
-    # TODO: COMMIT TRAN  (en el legacy: gSQLFile{PROP:SQL} = 'COMMIT TRAN')
-    # TODO: GBitacora('ACTUALIZAR FACTURA', invoice.invoice_number)
+    settings = AppSettingsService.get_resolved_settings(db, int(tenant_id), int(company_id))
+    q_settings = settings.get("qsisgen", {})
+    s_settings = settings.get("ssisgen", {})
 
-    # invoice.status and totals are set inside finalize_invoice_no_discharge / termina_ac_o_lp_normal
+    cal_val_base_tc = int(q_settings.get("calvalbasetcpedexpo") or s_settings.get("calvalbasetcpedexpo", 0))
+
+    # El TC ahora se resuelve dentro de assign_values (para per-line) 
+    # o dentro de _assign_invoice_totals (para base-pedimento-global).
+    # Sin embargo, para mantener compatibilidad con validaciones intermedias, lo dejamos aquí también:
+    exchange_rate = invoice.financials.exchange_rate if invoice.financials else 0
+    which_exchange_rate = "TCFAC"
+
+    if cal_val_base_tc == 1:
+        if invoice.compliance_mx and invoice.compliance_mx.pedimento:
+            ped = invoice.compliance_mx.pedimento
+            if ped.pedimento_dates and ped.pedimento_dates.payment_date:
+                payment_date = ped.pedimento_dates.payment_date
+                from sqlalchemy import select
+                stmt = select(ExchangeRate).where(
+                    ExchangeRate.tenant_id == int(tenant_id),
+                    ExchangeRate.company_id == int(company_id),
+                    ExchangeRate.date == payment_date.date())
+                ex_rate_row = db.execute(stmt).scalar_one_or_none()
+                if ex_rate_row:
+                    exchange_rate = float(ex_rate_row.value)
+                    which_exchange_rate = "TCPED"
+
+    if invoice.compliance_mx: invoice.compliance_mx.which_exchange_rate = which_exchange_rate
+    if invoice.financials: invoice.financials.exchange_rate = exchange_rate
     db.flush()
 
+    review_exchange_rate(db, invoice, cal_val_base_tc, errors)
+    errors.raise_if_errors()
+
+    savepoint = db.begin_nested()
+    try:
+        invoice_type = (invoice.invoice_type or "").strip().upper()
+        
+        # 1. Lógica específica de NODES
+        if invoice_type == "NODES":
+            assign_no_discharges_items(lines, errors)
+            assign_no_discharges_series(db, lines, errors)
+        
+        # 2. Asignar valores (costos/pesos) a las partidas
+        assign_values(db, invoice, lines, tenant_id, company_id, cal_val_base_tc, errors)
+        errors.raise_if_errors()
+
+        # 3. Finalización (Límites, TC global, Auditoría, Descargas A24)
+        if invoice_type == "NODES":
+            finalize_invoice_no_discharge(db, invoice, lines, tenant_id, company_id, errors, username=username)
+        else:
+            # Lógica de descarga PEPS
+            to_discharge = collect_lines_to_discharge(db, invoice, lines, errors)
+            errors.raise_if_errors()
+
+            if to_discharge:
+                fill_available_balances(db, invoice, to_discharge, errors)
+                errors.raise_if_errors()
+
+                compare_balances(db, invoice, to_discharge, errors)
+                errors.raise_if_errors()
+
+                verify_consolidated(db, invoice, to_discharge, errors)
+                errors.raise_if_errors()
+
+            finalize_invoice_with_discharge(
+                db, invoice, lines, tenant_id, company_id, errors, 
+                to_discharge=to_discharge, username=username
+            )
+        
+        errors.raise_if_errors()
+        savepoint.commit()
+
+    except Exception as e:
+        savepoint.rollback()
+        raise e
+
+    db.flush()
     return {"status": "success", "invoice_id": str(invoice.id)}
diff --git a/backend/api/v1/modules/a76/invoices/exports/process/pre_validators.py b/backend/api/v1/modules/a76/invoices/exports/process/pre_validators.py
index 8f1140f0..db1cb160 100644
--- a/backend/api/v1/modules/a76/invoices/exports/process/pre_validators.py
+++ b/backend/api/v1/modules/a76/invoices/exports/process/pre_validators.py
@@ -4,6 +4,7 @@ from api.v1.modules.a76.invoices.models import InvoiceHeader, InvoiceStatus
 from api.v1.modules.a76.items.models import LineItem
 from api.v1.modules.a76.general_catalogs.fractions.warning_fractions.models import WarningFraction
 from api.v1.modules.a76.clients_and_providers.models import ClientProvider
+from api.v1.modules.a76.app_settings.service import AppSettingsService
 from core.exceptions import ErrorCollector
 
 def pre_validators(db: Session, invoice: InvoiceHeader, tenant_id: str, company_id: str,  errors: ErrorCollector):
@@ -72,10 +73,24 @@ def pre_validators(db: Session, invoice: InvoiceHeader, tenant_id: str, company_
     elif invoice.financials.currency == "manual" and not invoice.financials.currency_type:
         errors.add_required_error("financials.currency_type")
         
-    #TODO: SSISGEN: Seguridad Ejemplo en:  BrowseQFacImp 
-    
-    # 2.- Existe tipo de cambio para la factura seleccionada    
-    #TODO: SSISGEN: VALIDACION DEL TIPO DE CAMBIO EN BASE A LA FECHA DE PAGO DEL PEDIMENTO.
+    # Validación de estatus de pedimento
+    # Validation of Pedimento status (CERRADO / PAGADO)
+    settings = AppSettingsService.get_resolved_settings(db, int(tenant_id), int(company_id))
+    expo_params = settings.get("ssisexpo", {})
+    # Resolver validarestatusped (podría estar en ssisexpo o qsisgen según el tipo de factura)
+    valida_estatus = int(expo_params.get("validarestatusped", 0))
+
+    if valida_estatus == 1:
+        if invoice.compliance_mx and invoice.compliance_mx.pedimento:
+            ped = invoice.compliance_mx.pedimento
+            if ped.pedimento_dates and ped.pedimento_dates.payment_date:
+                errors.add_error(
+                    field="compliance_mx.pedimento",
+                    message=f"No se puede procesar la factura porque el pedimento {ped.pedimento_number} ya se encuentra pagado el {ped.pedimento_dates.payment_date.date()}.",
+                    solution=["Desactive el parámetro 'validarestatusped' o rectifique el pedimento si requiere cambios."],
+                    code="PEDIMENTO_ALREADY_PAID"
+                )
+                errors.raise_if_errors()
 
     # 3.- Validacion que deber de existir un pedimento cuando es requerido
     if not invoice.compliance_mx.is_pedimento_pending and not invoice.compliance_mx.pedimento_id:
diff --git a/backend/api/v1/modules/a76/invoices/exports/process/routes.py b/backend/api/v1/modules/a76/invoices/exports/process/routes.py
index 2bd193bd..4014ae1e 100644
--- a/backend/api/v1/modules/a76/invoices/exports/process/routes.py
+++ b/backend/api/v1/modules/a76/invoices/exports/process/routes.py
@@ -26,16 +26,18 @@ def trigger_invoice_process(
     """
     tenant_id = validate_access_to_resource(db, company_id, current_user)
 
+    username = current_user.get("preferred_username") or current_user.get("email") or current_user.get("sub") or "SYSTEM"
+
     task = track_and_dispatch(
         db=db,
         task=process_export_invoice_task,
         tenant_id=tenant_id,
         company_id=company_id,
-        requested_by_user=current_user.get("preferred_username") or current_user.get("email") or current_user.get("sub"),
+        requested_by_user=username,
         task_name="process_export_invoice_task",
         task_group="invoices",
         task_origin="a76/invoices/exports/process",
-        args=[invoice_id, str(tenant_id), str(company_id)],
+        args=[invoice_id, str(tenant_id), str(company_id), username],
     )
 
     return {"task_id": task.id}
diff --git a/backend/api/v1/modules/a76/invoices/exports/process/sub_process/assign_values.py b/backend/api/v1/modules/a76/invoices/exports/process/sub_process/assign_values.py
index 2dc6b770..aa401166 100644
--- a/backend/api/v1/modules/a76/invoices/exports/process/sub_process/assign_values.py
+++ b/backend/api/v1/modules/a76/invoices/exports/process/sub_process/assign_values.py
@@ -3,7 +3,7 @@ ASIGNA_VALORES_PARTIDAS_ASIGNA_PESOS
 Resets and recalculates unit costs, export values
 (KGS ↔ LBS) for every line item of an export invoice.
 
-Two cost-assignment strategies (controlled by SisExp:ValFactTC — TODO):
+Two cost-assignment strategies (controlled by SisExp:ValFactTC):
   TCE  → bulk SQL UPDATE using the invoice-level exchange rate (Loc:TipoCambio).
   else → per-line loop that resolves each line's exchange rate from its
          source import invoice (TEM → QFacImp, DEF → QFacImpDef).
@@ -140,12 +140,12 @@ def _get_source_invoice_tc(
 
     Legacy fields:
         EqiPex:TipoMovImpo  → line.customs.origin_procedure
-        EqiPex:FacturaImpo  → line.reference.import_invoice  (TODO: confirm field)
+        EqiPex:FacturaImpo  → line.fa_data.search_invoice
     """
     fallback_tc = Decimal(str(invoice.financials.exchange_rate or 0))
 
     movement_type = (line.customs.origin_procedure or "").strip().upper() if line.customs else ""
-    import_invoice_number = (line.reference.import_invoice if line.reference else None) or ""
+    import_invoice_number = (line.fa_data.search_invoice if getattr(line, "fa_data", None) else None) or ""
 
     if not import_invoice_number:
         return fallback_tc
@@ -200,6 +200,7 @@ def assign_values(
     lines: List[LineItem],
     tenant_id: str,
     company_id: str,
+    cal_val_base_tc: int,
     errors: ErrorCollector,
 ) -> None:
     """
@@ -216,11 +217,29 @@ def assign_values(
     
 
     # --- Step 1: Assign costs / values ---------------------------------------
-    # TODO: Read SisExp:ValFactTC from the export system parameters model.
-    #       When ValFactTC = 'TCE' use _assign_costs_tce (single TC for all lines).
-    #       Otherwise use _assign_costs_per_line (TC from each source import invoice).
-    #       For now the per-line strategy is always used as the safe default.
-    val_fact_tc = "PER_LINE"  # TODO: replace with SisExp.val_fact_tc
+    # Resolve Settings for Strategy
+    from api.v1.modules.a76.app_settings.service import AppSettingsService
+    settings = AppSettingsService.get_resolved_settings(db, int(tenant_id), int(company_id))
+    
+    inv_type = (invoice.invoice_type or "").strip().upper()
+    op_type = "exp"
+    
+    # Hierarchical resolve: invoices.types.exp.{type}.ssisgen.ssimpFormData
+    inv_map = settings.get("invoices", {}).get("types", {}).get(op_type, {}).get(inv_type, {})
+    form_data = inv_map.get("ssisgen", {}).get("ssimpFormData", {}) or inv_map.get("qsisgen", {}).get("ssimpFormData", {}) or settings.get("ssisexpo", {})
+    
+    # Parameter ValFactTC: TCE (Encabezado) vs PER_LINE (Partida)
+    val_fact_tc = (form_data.get("valfacttc") or form_data.get("ValFactTC") or "").strip().upper()
+    
+    # Fallback/Auto-resolve:
+    # Si la configuración indica usar el TC del Pedimento (cal_val_base_tc = 1),
+    # usualmente forzamos TCE porque el encabezado ya fue nivelado al pago del pedimento.
+    if cal_val_base_tc == 1:
+        val_fact_tc = "TCE"
+    
+    # Default if empty
+    if not val_fact_tc:
+        val_fact_tc = "PER_LINE"
 
     if val_fact_tc == "TCE":
         _assign_costs_tce(lines, currency, tc, tc_mm)
diff --git a/backend/api/v1/modules/a76/invoices/exports/process/sub_process/fill_available_balances.py b/backend/api/v1/modules/a76/invoices/exports/process/sub_process/fill_available_balances.py
index eec6f686..32d33a0b 100644
--- a/backend/api/v1/modules/a76/invoices/exports/process/sub_process/fill_available_balances.py
+++ b/backend/api/v1/modules/a76/invoices/exports/process/sub_process/fill_available_balances.py
@@ -152,15 +152,9 @@ def fill_available_balances(
 ) -> None:
     """
     LLENA_QUEUE_SALDOS_DISPONIBLES_FACTURA
-    Validates each discharge entry and populates ``entry.available_lots``
-    with the net balance available from the PEPS ledger.
-
-    Parameters
-    ----------
-    db              : active SQLAlchemy session
-    export_invoice  : the export invoice being processed
-    to_discharge    : list of DownloadEntry objects (QueADescargar)
-    errors          : shared error collector
+    Refactorizada para PEPS Flexible:
+    Busca automáticamente todos los lotes con saldo disponible para el número de parte 
+    de cada partida a descargar.
     """
     export_date: datetime.date = (
         export_invoice.invoice_date.date()
@@ -168,109 +162,60 @@ def fill_available_balances(
         else export_invoice.invoice_date
     )
 
-    # Sort mirrors Clarion: Sort(QueADescargar, FacturaImpo, LineaImpo)
-    sorted_entries = sorted(
-        to_discharge,
-        key=lambda e: (e.import_invoice, e.import_line),
-    )
-
-    # Track already-resolved (invoice, line) pairs to skip duplicates
-    seen: set = set()
-
-    for entry in sorted_entries:
-        key = (entry.import_invoice, entry.import_line)
-        if key in seen:
-            continue
-        seen.add(key)
-
-        if not entry.import_invoice or entry.import_line == 0:
+    for entry in to_discharge:
+        # Recuperar la partida de exportación original para obtener IDs precisos
+        export_line = db.get(LineItem, entry.line_item_id)
+        if not export_line:
             continue
 
-        # ── 1. Validate import invoice ────────────────────────────────────────
-        import_invoice = _fetch_import_invoice(db, entry.import_invoice, export_invoice)
-
-        if import_invoice is None:
-            errors.add_error(
-                field=f"line[{entry.export_line}].import_invoice",
-                message=f"La Factura de Importación: '{entry.import_invoice}' no existe.",
-                solution=["Seleccionar otra factura de Importación."],
-                code="IMPORT_INVOICE_NOT_FOUND",
-                value=entry.import_invoice,
+        part_id = export_line.part_number_id
+        class_id = export_line.class_id
+        
+        # 1. Buscar todos los lotes candidatos (Importaciones del mismo número de parte y clase)
+        # Solo facturas procesadas y con fecha <= export_date
+        candidates = (
+            db.query(LineItem)
+            .join(InvoiceHeader, InvoiceHeader.id == LineItem.invoice_id)
+            .filter(
+                LineItem.tenant_id == export_invoice.tenant_id,
+                LineItem.company_id == export_invoice.company_id,
+                LineItem.part_number_id == part_id,
+                LineItem.class_id == class_id,
+                InvoiceHeader.operation_type == "imp",
+                InvoiceHeader.status != InvoiceStatus.PENDING,
+                InvoiceHeader.invoice_date <= export_date
             )
-            continue
-
-        # Status 'NA' == not processed (Clarion: Estatus = 'NA')
-        if import_invoice.status == InvoiceStatus.PENDING:
-            errors.add_error(
-                field=f"line[{entry.export_line}].import_invoice",
-                message=f"La Factura de Importación: '{entry.import_invoice}' está Desactualizada.",
-                solution=["Actualizar la factura de Importación."],
-                code="IMPORT_INVOICE_UNPROCESSED",
-                value=entry.import_invoice,
-            )
-            continue
-
-        # Import date must not be later than export date
-        imp_date: datetime.date = (
-            import_invoice.invoice_date.date()
-            if hasattr(import_invoice.invoice_date, "date")
-            else import_invoice.invoice_date
-        )
-        if imp_date > export_date:
-            errors.add_error(
-                field=f"line[{entry.export_line}].import_invoice",
-                message=(
-                    f"La Factura de Importación: '{entry.import_invoice}' tiene una Fecha Mayor "
-                    f"a la Fecha de Descarga."
-                ),
-                solution=[
-                    f"Seleccionar otra factura de Importación con Fecha Anterior al "
-                    f"{export_date.strftime('%d/%m/%Y')}."
-                ],
-                code="IMPORT_INVOICE_DATE_AFTER_EXPORT",
-                value={"import_date": str(imp_date), "export_date": str(export_date)},
-            )
-            continue
-
-        # ── 2. Validate import line ───────────────────────────────────────────
-        import_line = _fetch_import_line(
-            db,
-            import_invoice.id,
-            entry.import_line,
-            export_invoice.tenant_id,
-            export_invoice.company_id,
+            .all()
         )
 
-        if import_line is None:
+        # 2. Calcular saldos para cada candidato y llenar available_lots
+        found_any_balance = False
+        for imp_line in candidates:
+            available = _net_balance_for_lot(db, imp_line.id, export_date)
+            
+            if available > 0:
+                found_any_balance = True
+                fin = imp_line.financial
+                lot = AvailableLot(
+                    import_item_line_id=imp_line.id,
+                    import_invoice_id=imp_line.invoice_id,
+                    part_number_id=imp_line.part_number_id,
+                    available_qty=available,
+                    value_me=Decimal(str(fin.value_usd or 0)) if fin else None,
+                    value_mn=Decimal(str(fin.value_mxn or 0)) if fin else None,
+                    order_peps=_peps_order_for_lot(db, imp_line.id),
+                )
+                entry.available_lots.append(lot)
+
+        # 3. Ordenar por PEPS (FIFO)
+        entry.available_lots.sort(key=lambda x: x.order_peps)
+
+        # 4. Manejo de Errores: Solo si no se encontró ABSOLUTAMENTE NADA de saldo
+        if not found_any_balance:
             errors.add_error(
-                field=f"line[{entry.export_line}].import_line",
-                message=(
-                    f"La Factura de Importación: '{entry.import_invoice}' "
-                    f"con Línea: {entry.import_line} no existe."
-                ),
-                solution=["Seleccionar otra Línea de Importación a Descargar."],
-                code="IMPORT_LINE_NOT_FOUND",
-                value={"import_invoice": entry.import_invoice, "import_line": entry.import_line},
+                field=f"line[{entry.export_line}].quantity",
+                message=f"No se encontró saldo disponible en inventario para el número de parte: {entry.part_number}",
+                solution=["Verificar que existan facturas de importación procesadas con saldo."],
+                code="NO_BALANCE_FOUND_ANYWHERE",
+                value=entry.part_number,
             )
-            continue
-
-        # ── 3. Compute net available balance from ledger (as of export date) ───
-        # Equivalent to: CantImpo - CantRetornadaTemp - CantRetornada (general)
-        # then CALCULA_SALDO_FECHA_EXPO (only exits on or before export_date).
-        available = _net_balance_for_lot(db, import_line.id, export_date)
-        if available <= 0:
-            # No balance — skip this lot (equivalent to Clarion CYCLE)
-            continue
-
-        # ── 4. Build AvailableLot and attach to entry ─────────────────────────
-        fin = import_line.financial
-        lot = AvailableLot(
-            import_item_line_id=import_line.id,
-            import_invoice_id=import_invoice.id,
-            part_number_id=import_line.part_number_id,
-            available_qty=available,
-            value_me=Decimal(str(fin.value_usd or 0)) if fin else None,
-            value_mn=Decimal(str(fin.value_mxn or 0)) if fin else None,
-            order_peps=_peps_order_for_lot(db, import_line.id),
-        )
-        entry.available_lots.append(lot)
diff --git a/backend/api/v1/modules/a76/invoices/exports/process/sub_process/finalize_invoice.py b/backend/api/v1/modules/a76/invoices/exports/process/sub_process/finalize_invoice.py
index 7ea735dc..36e8b308 100644
--- a/backend/api/v1/modules/a76/invoices/exports/process/sub_process/finalize_invoice.py
+++ b/backend/api/v1/modules/a76/invoices/exports/process/sub_process/finalize_invoice.py
@@ -3,14 +3,14 @@ finalize_invoice_no_discharge / finalize_invoice_with_discharge
 (TERMINA_AC_O_LP_NODES / TERMINA_AC_O_LP_NORMAL)
 
 Last step of export invoice processing.  Both variants:
-  1. TODO: DO REVISACLASESHABILITADAS
+  1. Review enabled classes (REVISACLASESHABILITADAS).
   2. Validate SisExp quantity / weight / value limits (min and max).
   3. If no errors: assign invoice-level totals and mark as PROCESSED.
 
 The "with_discharge" variant additionally:
-  4. DO GENERAIMPODEFINITIVA             (if is_regime_change and generate_id)
-  5. DO REGISTRA_DESCARGA_IMPORTACION   (update returned qty/value on import lines)
-  6. DO REGISTRA_DESCARGA_SERIES        (flag import series as exported)
+  4. Generate definitive import (GENERAIMPODEFINITIVA) (if is_regime_change and generate_id)
+  5. Register discharge in import lines (REGISTRA_DESCARGA_IMPORTACION)
+  6. Register series discharge (REGISTRA_DESCARGA_SERIES)
 
 The legacy 'Of LP' branch (print-preview / progress-bar UI) is not ported.
 """
@@ -33,7 +33,7 @@ from api.v1.modules.a76.invoices.models import InvoiceHeader, InvoiceStatus
 from api.v1.modules.a76.items.models import LineItem
 from core.exceptions import ErrorCollector
 from .review_limits import limit_weight, limit_value
-from .generate_definitive_import import generate_definitive_import
+from .generate_definitive_import import generate_definitive_import, is_regime_change_detected
 
 
 # ---------------------------------------------------------------------------
@@ -69,118 +69,38 @@ def _review_enabled_classes(
             )
 
 
-# ---------------------------------------------------------------------------
-# SisExp limit checks  (shared by both public functions)
-# ---------------------------------------------------------------------------
-
-def _validate_sisexp_limits(
-    invoice: InvoiceHeader,
-    total_qty: Decimal,
-    total_net_weight: Decimal,
-    total_value: Decimal,
-    errors: ErrorCollector,
-) -> None:
-    """
-    Validates invoice totals against the SisExp min/max limit parameters.
-
-    TODO: Read actual SisExp parameters from the tenant system-config model.
-          Until then all limits default to 0 (= disabled) so no checks fire.
-
-    Clarion names → Python (TODO):
-      SisExp:CantLimiteMin  / SisExp:CantLimite   → qty    min / max
-      SisExp:PesoLimiteMin  / SisExp:PesoLimite   → weight min / max
-      SisExp:ValorLimiteMin / SisExp:ValorLimite  → value  min / max
-    """
-    # TODO: load from SisExp tenant config
-    cant_limite_min:  Decimal = Decimal(0)
-    cant_limite:      Decimal = Decimal(0)
-    peso_limite_min:  Decimal = Decimal(0)
-    peso_limite:      Decimal = Decimal(0)
-    valor_limite_min: Decimal = Decimal(0)
-    valor_limite:     Decimal = Decimal(0)
-
-    solution = ["Consulte a su Administrador de sistema para parametrizar la factura."]
-    code     = "PAR.EXPO"
-
-    if cant_limite_min != 0 and cant_limite_min > total_qty:
-        errors.add_error(
-            field="invoice.total_quantity",
-            message=(
-                f"La cantidad total de la factura: {total_qty} "
-                f"no supera a la cantidad mínima parametrizada: {cant_limite_min}."
-            ),
-            solution=solution, code=code,
-        )
-    if cant_limite != 0 and cant_limite < total_qty:
-        errors.add_error(
-            field="invoice.total_quantity",
-            message=(
-                f"La cantidad total de la factura: {total_qty} "
-                f"excede a la cantidad máxima parametrizada: {cant_limite}."
-            ),
-            solution=solution, code=code,
-        )
-    if peso_limite_min != 0 and peso_limite_min > total_net_weight:
-        errors.add_error(
-            field="invoice.net_weight",
-            message=(
-                f"El Peso Neto total de la factura: {total_net_weight} "
-                f"no supera el Peso mínimo parametrizado: {peso_limite_min}."
-            ),
-            solution=solution, code=code,
-        )
-    if peso_limite != 0 and peso_limite < total_net_weight:
-        errors.add_error(
-            field="invoice.net_weight",
-            message=(
-                f"El Peso Neto total de la factura: {total_net_weight} "
-                f"excede el Peso máximo parametrizado: {peso_limite}."
-            ),
-            solution=solution, code=code,
-        )
-    if valor_limite_min != 0 and valor_limite_min > total_value:
-        errors.add_error(
-            field="invoice.total_value",
-            message=(
-                f"El Valor total de la factura: {total_value} "
-                f"no supera el Valor mínimo parametrizado: {valor_limite_min}."
-            ),
-            solution=solution, code=code,
-        )
-    if valor_limite != 0 and valor_limite < total_value:
-        errors.add_error(
-            field="invoice.total_value",
-            message=(
-                f"El Valor total de la factura: {total_value} "
-                f"excede el Valor máximo parametrizado: {valor_limite}."
-            ),
-            solution=solution, code=code,
-        )
-
-
 # ---------------------------------------------------------------------------
 # DO ASIGNA_VALORES_FACTURA
 # ---------------------------------------------------------------------------
+from api.v1.modules.a76.app_settings.service import AppSettingsService
+from api.v1.modules.a76.general_catalogs.exchange_rate.models import ExchangeRate
+from sqlalchemy import select
+from .review_limits import review_sisexpo_limits
 
 def _assign_invoice_totals(
+    db: Session,
     invoice: InvoiceHeader,
     lines: List[LineItem],
+    tenant_id: str,
+    company_id: str,
+    username: str = "SYSTEM"
 ) -> None:
     """
     DO ASIGNA_VALORES_FACTURA
-    Aggregates line-level values (MN, ME, qty, packages, net/gross weight)
-    and writes the totals to the invoice header, then marks it as PROCESSED.
-
-    Clarion equivalent:
-      SELECT SUM(ValorExpoMN), SUM(ValorExpoME), SUM(CantExpo),
-             SUM(CantBultos),  SUM(PesoNeto),    SUM(PesoBruto)
-      FROM   QEqeMaq WHERE Consecutivo = <invoice.id>
-
-    TODO: SisGen:CalValBaseTCPedExpo = 1 → invoice.financials.exchange_rate = Loc:TipoCambio
-    TODO: SisGen:CalValBaseTCPedExpo = 1 →
-          invoice.process_log = 'Se Actualizó con el Tipo de Cambio de la Fecha de Pago de Pedimento.'
-    TODO: SisGen:ActSeguridad = 1 → invoice.updated_by = current_user
+    Calcula totales, resuelve TC base pedimento si aplica, y marca como PROCESADO.
     """
+    settings = AppSettingsService.get_resolved_settings(db, int(tenant_id), int(company_id))
+    
+    inv_type = (invoice.invoice_type or "").strip().upper()
+    op_type = (invoice.operation_type or "").strip().lower() # 'imp' or 'exp'
+    
+    # Hierarchical resolve: invoices.types.{op}.{type}.ssisgen.ssimpFormData
+    inv_map = settings.get("invoices", {}).get("types", {}).get(op_type, {}).get(inv_type, {})
+    form_data = inv_map.get("ssisgen", {}).get("ssimpFormData", {}) or inv_map.get("qsisgen", {}).get("ssimpFormData", {}) or settings.get("ssisgen", {}) or settings.get("qsisgen", {})
+
+    cal_val_base_tc = int(form_data.get("calvalbasetcpedexpo") or form_data.get("CalValBaseTCPedExpo") or 0)
+    act_seguridad = int(form_data.get("actseguridad") or form_data.get("ActSeguridad") or 0)
+
     total_value_mn  = Decimal(0)
     total_value_me  = Decimal(0)
     total_qty       = Decimal(0)
@@ -198,6 +118,23 @@ def _assign_invoice_totals(
             total_net_weight   += line.quantity.net_weight      or Decimal(0)
             total_gross_weight += line.quantity.gross_weight    or Decimal(0)
 
+    # 1. Resolver TC base pedimento si aplica
+    if cal_val_base_tc == 1:
+        if invoice.compliance_mx and invoice.compliance_mx.pedimento:
+            ped = invoice.compliance_mx.pedimento
+            if ped.pedimento_dates and ped.pedimento_dates.payment_date:
+                payment_date = ped.pedimento_dates.payment_date
+                stmt = select(ExchangeRate).where(
+                    ExchangeRate.tenant_id == int(tenant_id),
+                    ExchangeRate.company_id == int(company_id),
+                    ExchangeRate.date == payment_date.date())
+                ex_rate_row = db.execute(stmt).scalar_one_or_none()
+                if ex_rate_row and invoice.financials:
+                    invoice.financials.exchange_rate = float(ex_rate_row.value)
+                    invoice.compliance_mx.which_exchange_rate = "TCPED"
+                    invoice.process_log = "Se Actualizó con el Tipo de Cambio de la Fecha de Pago de Pedimento."
+    
+    # 2. Asignar totales al header
     if invoice.financials is not None:
         invoice.financials.value_mn      = float(total_value_mn)
         invoice.financials.value_me      = float(total_value_me)
@@ -210,6 +147,16 @@ def _assign_invoice_totals(
     invoice.updated_date = datetime.date.today()
     invoice.status       = InvoiceStatus.PROCESSED
 
+    # 3. Auditoría (ActSeguridad)
+    if act_seguridad == 1:
+        invoice.updated_by = username
+        from api.v1.modules.a76.audit_log.services.service import AuditService
+        AuditService.create_audit_log(
+            db=db, reference=invoice.invoice_number, procedure="ACTUALIZAR FACTURA", movement="EXPORTACION",
+            username=username, tenant_id=int(tenant_id), company_id=int(company_id),
+            table_name="invoice_header", record_id=str(invoice.id), operation_type="UPDATE"
+        )
+
 
 # ---------------------------------------------------------------------------
 # Public entry points
@@ -219,60 +166,63 @@ def finalize_invoice_no_discharge(
     db: Session,
     invoice: InvoiceHeader,
     lines: List[LineItem],
+    tenant_id: str,
+    company_id: str,
     errors: ErrorCollector,
+    username: str = "SYSTEM",
 ) -> None:
     """
     TERMINA_AC_O_LP_NODES
     Finalizes a NODES-type export invoice (no inventory discharge).
-
-    Flow:
-      1. Verify all line classes are active (REVISACLASESHABILITADAS).
-      2. Validate SisExp limits (qty / weight / value).
-      3. If no errors: write invoice totals and set status = PROCESSED.
     """
     _review_enabled_classes(db, invoice, lines, errors)
 
     total_qty, total_net_weight = limit_weight(lines)
     total_value                 = limit_value(lines)
 
-    _validate_sisexp_limits(invoice, total_qty, total_net_weight, total_value, errors)
+    settings = AppSettingsService.get_resolved_settings(db, int(tenant_id), int(company_id))
+    review_sisexpo_limits(invoice, settings, total_qty, total_net_weight, total_value, errors)
 
     if not errors.has_errors():
-        _assign_invoice_totals(invoice, lines)
+        _assign_invoice_totals(db, invoice, lines, tenant_id, company_id, username)
 
 
 def finalize_invoice_with_discharge(
     db: Session,
     invoice: InvoiceHeader,
     lines: List[LineItem],
+    tenant_id: str,
+    company_id: str,
     errors: ErrorCollector,
     to_discharge: List["DownloadEntry"] | None = None,
+    username: str = "SYSTEM",
 ) -> None:
-    """
-    TERMINA_AC_O_LP_NORMAL
-    Finalizes a discharge-type export invoice (AFIJO / DONAC / SCRAP / REEXP / VEMEX).
-
-    Flow:
-      1. Verify all line classes are active (REVISACLASESHABILITADAS).
-      2. Validate SisExp limits (qty / weight / value).
-      3. If no errors:
-         a. DO GENERAIMPODEFINITIVA        (only if is_regime_change and generate_id)
-         b. TODO: DO REGISTRA_DESCARGA_IMPORTACION  (write a24 discharge movements)
-         c. TODO: DO REGISTRA_DESCARGA_SERIES       (write series discharge records)
-         d. Write invoice totals and set status = PROCESSED.
-
-    Note: the legacy 'Of LP' branch (print-preview UI) is not ported.
-    """
+    # Refrescar factura para asegurar info de compliance/pedimentos fresca
+    db.refresh(invoice)
     _review_enabled_classes(db, invoice, lines, errors)
 
     total_qty, total_net_weight = limit_weight(lines)
     total_value                 = limit_value(lines)
 
-    _validate_sisexp_limits(invoice, total_qty, total_net_weight, total_value, errors)
+    settings = AppSettingsService.get_resolved_settings(db, int(tenant_id), int(company_id))
+    review_sisexpo_limits(invoice, settings, total_qty, total_net_weight, total_value, errors)
 
     if not errors.has_errors():
-        if invoice.compliance_mx and invoice.compliance_mx.is_regime_change and invoice.generate_id:
-            generate_definitive_import(db, invoice, errors)
+        # Unified detection of Regime Change (F4, CR type, or Manual Flag)
+        if is_regime_change_detected(invoice, settings):
+            def_invoice, created = generate_definitive_import(db, invoice, to_discharge or [], settings, errors)
+            if created and not errors.has_errors():
+                from .generate_definitive_import import (
+                    generate_definitive_import_all_lines,
+                    generate_definitive_import_discharged_lines
+                )
+                # Choice based on generate_desc_parties
+                if (invoice.generate_desc_parties or "").strip() == 'Todas':
+                    generate_definitive_import_all_lines(db, invoice, def_invoice, errors)
+                else:
+                    generate_definitive_import_discharged_lines(
+                        db, invoice, def_invoice, to_discharge or [], errors
+                    )
 
         if to_discharge:
             # Write BalanceMovement (CONSUMPTION) + DischargeHeader + DischargeDetail
@@ -281,4 +231,4 @@ def finalize_invoice_with_discharge(
             register_import_discharge(db, invoice, to_discharge)
             register_discharge_series(db, invoice, to_discharge)
 
-        _assign_invoice_totals(invoice, lines)
+        _assign_invoice_totals(db, invoice, lines, tenant_id, company_id, username)
diff --git a/backend/api/v1/modules/a76/invoices/exports/process/sub_process/generate_definitive_import.py b/backend/api/v1/modules/a76/invoices/exports/process/sub_process/generate_definitive_import.py
index 221a7e86..b7031c98 100644
--- a/backend/api/v1/modules/a76/invoices/exports/process/sub_process/generate_definitive_import.py
+++ b/backend/api/v1/modules/a76/invoices/exports/process/sub_process/generate_definitive_import.py
@@ -24,6 +24,8 @@ GENERAIMPODEFINITIVA Routine
   END
 """
 
+from decimal import Decimal
+from typing import List
 from sqlalchemy import select
 from sqlalchemy.orm import Session
 
@@ -89,27 +91,17 @@ def _create_definitive_import_header(
         tenant_id=exp.tenant_id,
         company_id=exp.company_id,
         system=exp.system,
-        operation_type=OperationType.IMPORT,
-        invoice_type="IMD",
+        operation_type=OperationType.IMP,
+        invoice_type="DEF",
         invoice_number=exp.invoice_number,
         invoice_date=exp.invoice_date,
-        updated_date=exp.invoice_date,
         party_count=exp.party_count,
         generate_id=False,
         status=InvoiceStatus.PENDING,
 
-        # Clients / providers
-        provider_id=exp.provider_id,
-        sold_to_header="Vendido a:",
-        sold_to_id=exp.sold_to_id,
-        shipped_to_header="Enviado a:",
-        shipped_to_id=exp.shipped_to_id,
-        customs_broker_id=exp.customs_broker_id,
-        customs_broker_us_id=exp.customs_broker_us_id,
-
-        # Notes
-        notes=exp.notes,
-        notes_english=exp.notes_english,
+        # Comments (Mapped from original OBSERVACIONE/I)
+        observation_es=exp.observation_es,
+        observation_en=exp.observation_en,
     )
     db.add(def_invoice)
     db.flush()  # get def_invoice.id before creating child records
@@ -134,8 +126,8 @@ def _create_definitive_import_header(
 
     # ── Compliance / pedimento ────────────────────────────────────────────
     if exp_comp is not None:
-        from api.v1.modules.a76.invoices.models import InvoiceComplianceMX
-        def_comp = InvoiceComplianceMX(
+        from api.v1.modules.a76.invoices.models import InvoiceComplianceMx
+        def_comp = InvoiceComplianceMx(
             tenant_id=exp.tenant_id,
             company_id=exp.company_id,
             invoice_id=def_invoice.id,
@@ -143,6 +135,15 @@ def _create_definitive_import_header(
             remesa=exp_comp.remesa,
             pedimento_id=exp_comp.pedimento_id,
             is_pedimento_pending=exp_comp.is_pedimento_pending,
+            # Reubicados aquí (Correcto en el esquema unificado)
+            provider_id=exp_comp.provider_id,
+            sold_to_id=exp_comp.sold_to_id,
+            shipped_to_id=exp_comp.shipped_to_id,
+            customs_broker_id=exp_comp.customs_broker_id,
+            customs_broker_us_id=exp_comp.customs_broker_us_id,
+            provider_header=exp_comp.provider_header,
+            sold_to_header=exp_comp.sold_to_header,
+            shipped_to_header=exp_comp.shipped_to_header,
         )
         db.add(def_comp)
 
@@ -166,11 +167,78 @@ def _create_definitive_import_header(
 # Public entry point
 # ---------------------------------------------------------------------------
 
+def is_regime_change_detected(invoice: InvoiceHeader, settings: any = None) -> bool:
+    """
+    Detecta si la factura debe activar la generación de Importación Definitiva (DEF).
+    Usa el parámetro 'incambioregdesc' como interruptor maestro.
+    """
+    # 0. Interruptor Maestro (Configuración Global)
+    # Soporta Dict de JSON o Objetos Pydantic/SQLA
+    if settings:
+        # Búsqueda exhaustiva y recursiva del parámetro maestro
+        def find_in_obj(obj, target_key):
+            if isinstance(obj, dict):
+                for k, v in obj.items():
+                    if k.lower() == target_key.lower():
+                        return v
+                    res = find_in_obj(v, target_key)
+                    if res is not None: return res
+            elif hasattr(obj, '__dict__'):
+                # Soporte para objetos Pydantic/SQLAlchemy
+                dict_rep = obj.__dict__ if hasattr(obj, '__dict__') else {}
+                if hasattr(obj, 'dict') and callable(getattr(obj, 'dict')):
+                    try: dict_rep = obj.dict()
+                    except: pass
+                elif hasattr(obj, 'model_dump') and callable(getattr(obj, 'model_dump')):
+                    try: dict_rep = obj.model_dump()
+                    except: pass
+                
+                for k, v in dict_rep.items():
+                    # Ignorar propiedades privadas de SQLAlchemy
+                    if k.startswith('_'): continue
+                    if k.lower() == target_key.lower():
+                        return v
+                    res = find_in_obj(v, target_key)
+                    if res is not None: return res
+            return None
+
+        # Buscamos el valor en todo el árbol de configuración
+        val = find_in_obj(settings, 'incambioregdesc')
+        
+        # LOG DE EMERGENCIA en consola para debugging
+        print(f"[REGIME_CHANGE_DETECT] Factura: {invoice.invoice_number}, Valor de incambioregdesc: {val}")
+
+        # Comprobación segura (1, '1', True, 'true')
+        master_on = str(val).strip().lower() in ['1', 'true']
+        
+        if not master_on:
+            return False
+
+    # 1. Export + Pedimento F4 (Art. 114)
+    op_type = str(invoice.operation_type or "").lower()
+    if op_type == "exp":
+        if invoice.compliance_mx:
+            ped = invoice.compliance_mx.pedimento
+            if ped and (ped.pedimento_code or "").strip().upper() == "F4":
+                return True
+
+    # 2. Tipo de Factura 'CR' o Flag Manual
+    if (invoice.invoice_type or "").strip().upper() == "CR":
+        return True
+    
+    if invoice.compliance_mx and invoice.compliance_mx.is_regime_change:
+        return True
+            
+    return False
+
+
 def generate_definitive_import(
     db: Session,
     invoice: InvoiceHeader,
+    to_discharge: List[DownloadEntry],
+    settings: any,
     errors: ErrorCollector,
-) -> InvoiceHeader | None:
+) -> tuple[InvoiceHeader, bool]:
     """
     GENERAIMPODEFINITIVA
     Creates a definitive import invoice header from ``invoice`` (export) when
@@ -200,22 +268,16 @@ def generate_definitive_import(
             InvoiceHeader.tenant_id == invoice.tenant_id,
             InvoiceHeader.company_id == invoice.company_id,
             InvoiceHeader.invoice_number == invoice.invoice_number,
-            InvoiceHeader.invoice_type == "IMD",
+            InvoiceHeader.invoice_type == "DEF",
         )
     ).scalar_one_or_none()
 
     if existing is not None:
-        def_invoice = existing
-    else:
-        # ── 2. Create the definitiva header ──────────────────────────────────
-        def_invoice = _create_definitive_import_header(db, invoice)
+        return existing, False
 
-    # ── 3. Generate lines ────────────────────────────────────────────────────
-    # to_discharge / all_lines must be passed by the caller after this returns.
-    # See generate_definitive_import_all_lines() and
-    # generate_definitive_import_discharged_lines() below.
-
-    return def_invoice
+    # ── 2. Create the definitiva header ──────────────────────────────────
+    def_invoice = _create_definitive_import_header(db, invoice)
+    return def_invoice, True
 
 
 # ---------------------------------------------------------------------------
@@ -229,20 +291,27 @@ def _copy_line_to_definitive(
     export_line: LineItem,
     def_invoice: InvoiceHeader,
     def_line_number: int,
+    custom_qty: Decimal | None = None,
 ) -> None:
     """
     Copies a single export LineItem (and its series) into a new definitive
     import LineItem under ``def_invoice``.
 
-    Clarion fixed values:
-      EsSubPartida = 'P'  → is_subitem = False
-      ContieneSubP = 'N'  → contains_subitems = False
-      SubPartida   = 0    → subitem_number = 0
-      EsReparacion = 0    → (no repair flag needed)
+    If ``custom_qty`` is provided, the function scales weights and values
+    proportionally (Regime Change with Discharge logic).
     """
     from api.v1.modules.a76.items.line_financials.models import LineFinancial
     from api.v1.modules.a24.fa.fa_item_lines.models import FaLineItem
 
+    # Calculate proportionality ratio if custom_qty is provided
+    original_qty = export_line.quantity.quantity if export_line.quantity else Decimal(1)
+    if original_qty == 0:
+        original_qty = Decimal(1)
+    
+    ratio = Decimal(1)
+    if custom_qty is not None:
+        ratio = custom_qty / original_qty
+
     def_line = LineItem(
         tenant_id=def_invoice.tenant_id,
         company_id=def_invoice.company_id,
@@ -257,19 +326,36 @@ def _copy_line_to_definitive(
 
     if export_line.quantity:
         src_q = export_line.quantity
+        qty_val = custom_qty if custom_qty is not None else src_q.quantity
+        
         db.add(LineQuantity(
             item_line_id=def_line.id,
-            quantity=src_q.quantity,
-            net_weight=src_q.net_weight,
-            gross_weight=src_q.gross_weight,
-            package_quantity=src_q.package_quantity,
+            quantity=qty_val,
+            net_weight=(src_q.net_weight * ratio) if src_q.net_weight is not None else None,
+            gross_weight=(src_q.gross_weight * ratio) if src_q.gross_weight is not None else None,
+            package_quantity=int(src_q.package_quantity * ratio) if src_q.package_quantity is not None else None,
             package_id=src_q.package_id,
         ))
 
     if export_line.financial:
+        src_f = export_line.financial
+        
+        # Helper to scale optional Decimal fields
+        def scale(val: Decimal | None) -> Decimal | None:
+            return (val * ratio) if val is not None else None
+
         db.add(LineFinancial(
             item_line_id=def_line.id,
-            unit_cost_capture=export_line.financial.unit_cost_capture,
+            unit_cost_capture=src_f.unit_cost_capture,
+            unit_cost_usd=src_f.unit_cost_usd,
+            unit_cost_mxn=src_f.unit_cost_mxn,
+            # Scale total values
+            value_mxn=scale(src_f.value_mxn),
+            value_usd=scale(src_f.value_usd),
+            customs_value_mxn=scale(src_f.customs_value_mxn),
+            customs_value_usd=scale(src_f.customs_value_usd),
+            value_added_mxn=scale(src_f.value_added_mxn),
+            value_added_usd=scale(src_f.value_added_usd),
         ))
 
     if export_line.customs:
@@ -297,7 +383,9 @@ def _copy_line_to_definitive(
         ))
 
     db.add(FaLineItem(
-        item_line_id=def_line.id,
+        id=def_line.id,
+        tenant_id=def_line.tenant_id,
+        company_id=def_line.company_id,
         is_subitem=False,
         contains_subitems=False,
         subitem_number=0,
@@ -329,27 +417,51 @@ def generate_definitive_import_discharged_lines(
     db: Session,
     export_invoice: InvoiceHeader,
     def_invoice: InvoiceHeader,
-    to_discharge: list[DownloadEntry],
+    to_discharge: List[DownloadEntry],
     errors: ErrorCollector,
 ) -> None:
     """
     GENERAIMPODEFINITIVA_PARTIDAS_CON_DESCARGA
-    Creates definitive import lines only for the lines in the discharge list,
-    sorted by (import_invoice, import_line).
+    Creates definitive import lines only for the lots consumed in the discharge,
+    effectively splitting export lines if they came from multiple import batches.
 
     Clarion: Sort(QueADescargar, FacturaImpo, LineaImpo) → loop
     """
+    # Sort by import lot origin to match legacy behavior
     sorted_entries = sorted(
         to_discharge,
         key=lambda e: (e.import_invoice, e.import_line),
     )
+    
     def_line_number = 0
     for entry in sorted_entries:
         export_line: LineItem | None = db.get(LineItem, entry.line_item_id)
         if export_line is None:
             continue
-        def_line_number += 1
-        _copy_line_to_definitive(db, export_line, def_invoice, def_line_number)
+            
+        # If the entry has LOTS assigned (PEPS), create one IMD line per lot consumed
+        lots_to_transfer = [lot for lot in entry.available_lots if lot.consumed_qty > 0]
+        
+        if lots_to_transfer:
+            for lot in lots_to_transfer:
+                def_line_number += 1
+                _copy_line_to_definitive(
+                    db, 
+                    export_line, 
+                    def_invoice, 
+                    def_line_number, 
+                    custom_qty=lot.consumed_qty
+                )
+        else:
+            # Fallback: if no lot info but entry exists, use entry quantity
+            def_line_number += 1
+            _copy_line_to_definitive(
+                db, 
+                export_line, 
+                def_invoice, 
+                def_line_number, 
+                custom_qty=entry.quantity
+            )
 
     db.flush()
 
diff --git a/backend/api/v1/modules/a76/invoices/exports/process/sub_process/review_exchange_rate.py b/backend/api/v1/modules/a76/invoices/exports/process/sub_process/review_exchange_rate.py
index 9e3142e1..a44f4726 100644
--- a/backend/api/v1/modules/a76/invoices/exports/process/sub_process/review_exchange_rate.py
+++ b/backend/api/v1/modules/a76/invoices/exports/process/sub_process/review_exchange_rate.py
@@ -32,6 +32,7 @@ from core.exceptions import ErrorCollector
 def review_exchange_rate(
     db: Session,
     invoice: InvoiceHeader,
+    cal_val_base_tc: int,
     errors: ErrorCollector,
 ) -> None:
     """
@@ -43,10 +44,12 @@ def review_exchange_rate(
     ----------
     db      : active SQLAlchemy session
     invoice : the export invoice being processed
+    cal_val_base_tc : flag from settings (1 = skip validation as TC comes from pedimento)
     errors  : shared error collector
     """
-    # TODO: skip when SisGen:CalValBaseTCPedExpo = 1
-    #       (TC is taken from pedimento payment date, validated elsewhere)
+    if cal_val_base_tc == 1:
+        # SKIP: TC is taken from pedimento payment date, resolved in main_process Step 7
+        return
 
     if not invoice.financials:
         return
diff --git a/backend/api/v1/modules/a76/invoices/exports/process/sub_process/review_limits.py b/backend/api/v1/modules/a76/invoices/exports/process/sub_process/review_limits.py
index b62759f8..163177ac 100644
--- a/backend/api/v1/modules/a76/invoices/exports/process/sub_process/review_limits.py
+++ b/backend/api/v1/modules/a76/invoices/exports/process/sub_process/review_limits.py
@@ -1,80 +1,96 @@
-"""
-TOT_PAR_LIM_CANT_PESO / TOT_PAR_LIM_VALOR
-Computes invoice-level totals (quantity, net weight, capture value) from all
-line items and writes them back to the invoice financials.
-
-These totals are used downstream to enforce the SisExp limit parameters
-(CantLimite, PesoLimite, ValorLimite — TODO when SisExp model is available).
-
-Legacy equivalents
-------------------
-TOT_PAR_LIM_CANT_PESO:
-  SELECT SUM(CantExpo), SUM(PesoNeto)
-  FROM   QEqeMaq
-  WHERE  Consecutivo = <invoice.id>
-  → stored in Loc:CantExpoLim, Loc:PesoNetoLim
-
-TOT_PAR_LIM_VALOR:
-  SELECT SUM(CostoUnitarioCaptura * CantExpo)
-  FROM   QEqeMaq
-  WHERE  Consecutivo = <invoice.id>
-  → stored in Loc:ValorExpoLim
-"""
-
+import logging
 from decimal import Decimal
-from typing import List
-
+from typing import Dict, Any, List
 from api.v1.modules.a76.invoices.models import InvoiceHeader
-from api.v1.modules.a76.items.models import LineItem
 from core.exceptions import ErrorCollector
 
+logger = logging.getLogger(__name__)
 
-def limit_weight(    
-    lines: List[LineItem],    
-) -> tuple[Decimal, Decimal]:
+def review_sisexpo_limits(
+    invoice: InvoiceHeader,
+    settings: Dict[str, Any],
+    total_qty: Decimal,
+    total_net_weight: Decimal,
+    total_value: Decimal,
+    errors: ErrorCollector
+) -> None:
     """
-    TOT_PAR_LIM_CANT_PESO
-    Sums exported quantity and net weight across all line items and Returns the totals.
+    Validates invoice totals against the SisExpo min/max limit parameters.
+    Uses robust resolution for deep nested JSON structure.
+    """
+    invoice_type = (invoice.invoice_type or "").strip().upper()
+    op_type = "exp"
+    
+    # 1. Start from ssisexpo root
+    params = settings.get("ssisexpo", {})
+    cat_name = "ssisexpo"
 
-    Returns
-    -------
-    (total_quantity, total_net_weight)
-    after the call.
-    """
+    # 2. Deep resolution if not in root (Frontend structure)
+    # Search for any limit field to decide if we should deep dive
+    has_root_limits = any(params.get(k) is not None for k in ["cantlimite", "CantLimite", "pesolimite", "PesoLimite", "valorlimite", "ValorLimite"])
+    
+    if not has_root_limits:
+        invoice_map = settings.get("invoices", {}).get("types", {}).get(op_type, {}).get(invoice_type, {})
+        # Buscar en ssimpFormData (shared schema) dentro de qsisgen o ssisgen
+        params = invoice_map.get("qsisgen", {}).get("ssimpFormData", {}) or invoice_map.get("ssisgen", {}).get("ssimpFormData", {}) or params
+        cat_name = f"invoices.types.{op_type}.{invoice_type}.ssimpFormData"
+
+    # Obtener límites Máximos
+    limit_qty = Decimal(str(params.get("cantlimite") or params.get("CantLimite") or 0))
+    limit_weight = Decimal(str(params.get("pesolimite") or params.get("PesoLimite") or 0))
+    limit_value = Decimal(str(params.get("valorlimite") or params.get("ValorLimite") or 0))
+
+    # Obtener límites Mínimos
+    min_limit_qty = Decimal(str(params.get("cantlimitemin") or params.get("CantLimiteMin") or 0))
+    min_limit_weight = Decimal(str(params.get("pesolimitemin") or params.get("PesoLimiteMin") or 0))
+    min_limit_value = Decimal(str(params.get("valorlimitemin") or params.get("ValorLimiteMin") or 0))
+
+    logger.info(f"DEBUG_EXPO_LIMITS: Invoice={invoice.invoice_number} | DetectedType={invoice_type} | ResolvedCat={cat_name}")
+    logger.info(f"DEBUG_EXPO_LIMITS: RAW_PARAMS_FOR_VAL={params}") # Cuidado, esto puede ser largo pero nos dirá la verdad
+    logger.info(f"DEBUG_EXPO_LIMITS: Qty: Current={total_qty} Max={limit_qty} Min={min_limit_qty}")
+    logger.info(f"LIMIT_CHECK_EXPO: Weight: Current={total_net_weight} Max={limit_weight} Min={min_limit_weight}")
+    logger.info(f"LIMIT_CHECK_EXPO: Value: Current={total_value} Max={limit_value} Min={min_limit_value}")
+
+    solution = ["Ajuste los valores de la factura o consulte a su Administrador para parametrizar la factura."]
+    code = "PAR.EXPO"
+
+    # --- Max Validations ---
+    if limit_qty > 0 and total_qty > limit_qty:
+        errors.add_error(field="financials.total_quantity", message=f"La cantidad total ({total_qty}) excede el máximo permitido ({limit_qty}).", solution=solution, code=code)
+
+    if limit_weight > 0 and total_net_weight > limit_weight:
+        errors.add_error(field="financials.net_weight", message=f"El peso neto total ({total_net_weight}) excede el máximo permitido ({limit_weight}).", solution=solution, code=code)
+
+    if limit_value > 0 and total_value > limit_value:
+        errors.add_error(field="financials.value_me", message=f"El valor total en USD ({total_value}) excede el máximo permitido ({limit_value}).", solution=solution, code=code)
+
+    # --- Min Validations ---
+    if min_limit_qty > 0 and total_qty < min_limit_qty:
+        errors.add_error(field="financials.total_quantity", message=f"La cantidad total ({total_qty}) es inferior al mínimo requerido ({min_limit_qty}).", solution=solution, code=code)
+
+    if min_limit_weight > 0 and total_net_weight < min_limit_weight:
+        errors.add_error(field="financials.net_weight", message=f"El peso neto total ({total_net_weight}) es inferior al mínimo requerido ({min_limit_weight}).", solution=solution, code=code)
+
+    if min_limit_value > 0 and total_value < min_limit_value:
+        errors.add_error(field="financials.value_me", message=f"El valor total en USD ({total_value}) es inferior al mínimo requerido ({min_limit_value}).", solution=solution, code=code)
+
+
+def limit_weight(lines: List[Any]) -> tuple[Decimal, Decimal]:
+    """Sums exported quantity and net weight across all line items."""
     total_qty = Decimal(0)
     total_net_weight = Decimal(0)
-
     for line in lines:
-        if line.quantity is None:
-            continue
-        total_qty += line.quantity.quantity or Decimal(0)
-        total_net_weight += line.quantity.net_weight or Decimal(0)
-
+        if line.quantity:
+            total_qty += line.quantity.quantity or Decimal(0)
+            total_net_weight += line.quantity.net_weight or Decimal(0)
     return total_qty, total_net_weight
 
-
-def limit_value(        
-    lines: List[LineItem],    
-) -> Decimal:
-    """
-    TOT_PAR_LIM_VALOR
-    Sums (unit_cost_capture × quantity) across all line items and writes the
-    result to ``invoice.financials.value_mn`` as the capture-based total value.
-
-    Returns
-    -------
-    total_capture_value — also available on invoice.financials after the call.
-
-    Note: the legacy field Loc:ValorExpoLim is only used to compare against
-    SisExp limit parameters (TODO when SisExp model is available).
-    """
+def limit_value(lines: List[Any]) -> Decimal:
+    """Sums (unit_cost_capture × quantity) across all line items."""
     total_value = Decimal(0)
-
     for line in lines:
-        if line.financial is None or line.quantity is None:
-            continue
-        capture = line.financial.unit_cost_capture or Decimal(0)
-        qty = line.quantity.quantity or Decimal(0)
-        total_value += capture * qty
-
+        if line.financial and line.quantity:
+            capture = line.financial.unit_cost_capture or Decimal(0)
+            qty = line.quantity.quantity or Decimal(0)
+            total_value += capture * qty
     return total_value
diff --git a/backend/api/v1/modules/a76/invoices/exports/process/sub_process/series/review_qty_series.py b/backend/api/v1/modules/a76/invoices/exports/process/sub_process/series/review_qty_series.py
index 5d4a3200..07821730 100644
--- a/backend/api/v1/modules/a76/invoices/exports/process/sub_process/series/review_qty_series.py
+++ b/backend/api/v1/modules/a76/invoices/exports/process/sub_process/series/review_qty_series.py
@@ -25,11 +25,9 @@ from api.v1.modules.a76.general_catalogs.company.models import Company
 from api.v1.modules.a76.invoices.models import InvoiceHeader
 from api.v1.modules.a76.items.models import LineItem
 from api.v1.modules.a76.items.series.models import Serie
+from api.v1.modules.a76.app_settings.service import AppSettingsService
 from core.exceptions import ErrorCollector
 
-# TODO: Read SisGen:CantvsCantSeries from the tenant system-config model
-_SISGEN_CANT_VS_CANT_SERIES: int = 0  # 0 = disabled
-
 # RFCs where qty-vs-series validation is conditional on UOM = PZA when is_regime_change
 _RFC_EXCEPCION_PZA = {
     "IMS030409FZ0",
@@ -45,6 +43,7 @@ def _validate_line_series(
     line: LineItem,
     company_rfc: str,
     errors: ErrorCollector,
+    valida_cant_series: int = 0,
 ) -> None:
     """Validates series count for a single line that has has_serial = True."""
     series_count = (
@@ -66,8 +65,7 @@ def _validate_line_series(
         return
 
     # Rule 2: quantity vs series count check (controlled by SisGen flag)
-    # TODO: Replace _SISGEN_CANT_VS_CANT_SERIES with the real config value
-    if _SISGEN_CANT_VS_CANT_SERIES != 1:
+    if valida_cant_series != 1:
         return
 
     qty = line.quantity.quantity if line.quantity else None
@@ -114,8 +112,13 @@ def review_qty_series(
     company = db.get(Company, company_id)
     company_rfc = (company.rfc or "").strip().upper() if company else ""
 
+    settings = AppSettingsService.get_resolved_settings(db, int(tenant_id), int(company_id))
+    q_gen = settings.get("qsisgen", {})
+    s_gen = settings.get("ssisgen", {})
+    valida_cant_series = int(q_gen.get("cantvscantseries") or s_gen.get("cantvscantseries", 0))
+
     for line in lines:
         if not (line.description and line.description.has_serial):
             continue
 
-        _validate_line_series(db, invoice, line, company_rfc, errors)
+        _validate_line_series(db, invoice, line, company_rfc, errors, valida_cant_series)
diff --git a/backend/api/v1/modules/a76/invoices/exports/process/task.py b/backend/api/v1/modules/a76/invoices/exports/process/task.py
index 65bda45a..4048d2af 100644
--- a/backend/api/v1/modules/a76/invoices/exports/process/task.py
+++ b/backend/api/v1/modules/a76/invoices/exports/process/task.py
@@ -13,7 +13,7 @@ def _progress(task: Task, current: int, status: str) -> None:
 
 
 @celery_app.task(bind=True, name="process_export_invoice_task")
-def process_export_invoice_task(self: Task, invoice_id: int, tenant_id: str, company_id: str) -> dict:
+def process_export_invoice_task(self: Task, invoice_id: int, tenant_id: str, company_id: str, username: str = "SYSTEM") -> dict:
     """
     Procesa una factura de exportación ejecutando todas las validaciones y
     actualizaciones del proceso principal de exportación con reporte de progreso.
@@ -30,7 +30,7 @@ def process_export_invoice_task(self: Task, invoice_id: int, tenant_id: str, com
             }
 
         _progress(self, 10, "Procesando factura de exportación...")
-        result = main_process(db, invoice, tenant_id, company_id)
+        result = main_process(db, invoice, tenant_id, company_id, username=username)
 
         db.commit()
         _progress(self, 100, "Proceso completado.")
diff --git a/backend/api/v1/modules/a76/invoices/exports/revert/main_process.py b/backend/api/v1/modules/a76/invoices/exports/revert/main_process.py
index f264ea27..62fc16f5 100644
--- a/backend/api/v1/modules/a76/invoices/exports/revert/main_process.py
+++ b/backend/api/v1/modules/a76/invoices/exports/revert/main_process.py
@@ -1,3 +1,4 @@
+from api.v1.modules.a76.app_settings.service import AppSettingsService
 import datetime
 from decimal import Decimal
 from typing import List, Optional
@@ -28,15 +29,18 @@ def _validate_regime_change_definitive_invoice_exists(
     invoice: InvoiceHeader,
     errors: ErrorCollector,
 ) -> None:
-    """
-    Clarion mapping:
-      If EqiFex:EsCambioRegimen='S' then count QFacImpDef where
-      FacturaImpoDef = FacturaExpo and ProvImpoDefCR='C'.
-
-    Python approximation:
-      Search an import invoice with same invoice_number and invoice_type='IMD'.
-    """
-    if not (invoice.compliance_mx and invoice.compliance_mx.is_regime_change):
+    # Robust detection logic (same as generator)
+    is_cr = False
+    if invoice.compliance_mx and invoice.compliance_mx.is_regime_change:
+        is_cr = True
+    elif (invoice.invoice_type or "").strip().upper() == "CR":
+        is_cr = True
+    elif invoice.operation_type == OperationType.EXP:
+        if invoice.compliance_mx and invoice.compliance_mx.pedimento:
+            if (invoice.compliance_mx.pedimento.pedimento_code or "").strip().upper() == "F4":
+                is_cr = True
+    
+    if not is_cr:
         return
 
     if not invoice.invoice_number:
@@ -348,10 +352,7 @@ def revert_process(
     _ = (db, tenant_id, company_id)  # reserved for future TO DO implementations
     sql_errors: list = []
 
-    # INICIALIZA QUEUES (Python: collector ya llega limpio por tarea)
-    # TODO: Compartir QSisGen / parámetros globales del Clarion.
-
-    # TODO: BEGIN TRAN (managed by SQLAlchemy session in task)
+    # PROCESO DE REVERSIÓN
     _todo_check_access_lock(invoice)
 
     # VERIFICAR SI HAY PARTIDAS DE EXPORTACION
@@ -370,4 +371,19 @@ def revert_process(
     _set_invoice_unprocessed(invoice, line_count)
 
     # TODO: COMMIT/ROLLBACK TRAN + QueueErrorSQL file handling + GBitacora
+    
+    # Auditoría de Desactualización
+    settings = AppSettingsService.get_resolved_settings(db, int(tenant_id), int(company_id))
+    q_gen = settings.get("qsisgen", {})
+    s_gen = settings.get("ssisgen", {})
+    act_seguridad = int(q_gen.get("actseguridad") or s_gen.get("actseguridad") or q_gen.get("ActSeguridad") or s_gen.get("ActSeguridad", 0))
+    
+    if act_seguridad == 1:
+        from api.v1.modules.a76.audit_log.services.service import AuditService
+        AuditService.create_audit_log(
+            db=db, reference=invoice.invoice_number, procedure="ANULAR FACTURA", movement="DESACTUALIZACION",
+            username=cancelled_by or "SYSTEM", tenant_id=int(tenant_id), company_id=int(company_id),
+            table_name="invoice_header", record_id=str(invoice.id), operation_type="UPDATE"
+        )
+    
     return sql_errors
diff --git a/backend/api/v1/modules/a76/invoices/exports/validators/update.py b/backend/api/v1/modules/a76/invoices/exports/validators/update.py
index 7c4b5cd4..c6371453 100644
--- a/backend/api/v1/modules/a76/invoices/exports/validators/update.py
+++ b/backend/api/v1/modules/a76/invoices/exports/validators/update.py
@@ -24,7 +24,7 @@ def validate_update(
     errors: ErrorCollector,     
 ) -> None:
     """
-    Valida y procesa la actualización parcial de una factura de importación temporal.
+    Valida y procesa la actualización parcial de una factura de exportación.
     
     Lógica: Si un campo viene con valor, se limpia/valida.
            Si no, se mantiene el valor existente de la factura.
diff --git a/backend/api/v1/modules/a76/invoices/imports/process/main_process.py b/backend/api/v1/modules/a76/invoices/imports/process/main_process.py
index c4127ee9..e672f3e8 100644
--- a/backend/api/v1/modules/a76/invoices/imports/process/main_process.py
+++ b/backend/api/v1/modules/a76/invoices/imports/process/main_process.py
@@ -1,4 +1,5 @@
-
+import logging
+logger = logging.getLogger(__name__)
 from datetime import date, datetime
 from decimal import Decimal
 from typing import List
@@ -30,7 +31,10 @@ from .sub_process.assing_values_def_mex import (
     assign_values_invoice_totals,
 )
 from ..balance.create_balance_entries import create_balance_entries
+from .sub_process.review_limits import review_limits
 
+# Parameter Service
+from api.v1.modules.a76.app_settings.service import AppSettingsService
 
 
 def _validate_lines(
@@ -44,44 +48,34 @@ def _validate_lines(
     """Recorre cada partida y ejecuta las validaciones individuales."""
     company = db.get(Company, invoice.company_id)
     company_rfc = (company.rfc or "").strip().upper() if company else ""
-    # Deduplicación de cupos disponibles: (permiso, ro_line, pais) → OctaveAvailableEntry
     octave_available: dict = {}
-    # Partidas a descargar: se pasa a valida_imp_regla_octava
     octave_desc: list = []
+    
     for line in lines:
-        # Validar costo unitario capturado en partidas principales
         if (line.financial and line.fa_data) and not line.fa_data.is_subitem and (line.financial.unit_cost_capture or Decimal(0)) == 0:
             errors.add_error(
                 field=f"line[{line.line_number}].unit_cost_capture",
                 message="No existe el costo unitario para la Partida.",
-                solution=[
-                    f"Entrar a la partida: {line.line_number} y capturar el Costo Unitario."
-                ],
+                solution=[f"Entrar a la partida: {line.line_number} y capturar el Costo Unitario."],
                 code="UNIT_COST_REQUIRED",
             )
 
-        # Validar clase habilitada/deshabilitada
         if line.class_id is not None:
             cls: Class | None = db.get(Class, line.class_id)
             if cls and cls.is_active is False:
                 errors.add_error(
                     field=f"line[{line.line_number}].class",
-                    message=(
-                        f"El número de parte: {cls.class_code} esta desactivado, no se pueden hacer movimientos."
-                    ),
+                    message=f"El número de parte: {cls.class_code} esta desactivado, no se pueden hacer movimientos.",
                     solution=["Seleccionar un número de parte activo."],
                     code="CLASS_DISABLED",
                 )
 
-        # Validar número de parte habilitado/deshabilitado
         if line.part_number_id is not None:
             part: Part | None = db.get(Part, line.part_number_id)
             if part and part.is_active is False:
                 errors.add_error(
                     field=f"line[{line.line_number}].part_number",
-                    message=(
-                        f"El número de parte: {part.part_number} esta desactivado, no se pueden hacer movimientos."
-                    ),
+                    message=f"El número de parte: {part.part_number} esta desactivado, no se pueden hacer movimientos.",
                     solution=["Seleccionar un número de parte activo."],
                     code="PART_DISABLED",
                 )
@@ -96,37 +90,26 @@ def _validate_lines(
             errors=errors,
         )        
         
-        review_series(db, line, company_rfc, errors)
+        review_series(db, line, company_rfc, tenant_id, company_id, errors)
 
-        # Validación de la Regla Octava
         if line.octave_permit:
             if not company.prosec:
                 errors.add_error(
                     field=f"line[{line.line_number}].octave_permit",
-                    message="No se puede hacer uso de la Regla Octava, ...",
+                    message="No se puede hacer uso de la Regla Octava...",
                     solution=["Borrar el permiso o dar de alta el permiso PROSEC..."],
                     code="OCTAVA_SIN_PROSEC",
                 )
             else:
                 desc_entry = llena_impo_permiso_regla_octava(
-                    db=db,
-                    invoice=invoice,
-                    line=line,
-                    company_rfc=company_rfc,
-                    tenant_id=tenant_id,
-                    company_id=company_id,
-                    errors=errors,
+                    db=db, invoice=invoice, line=line, company_rfc=company_rfc,
+                    tenant_id=tenant_id, company_id=company_id, errors=errors,
                 )
                 if desc_entry is not None:
                     octave_desc.append(desc_entry)
                 available = revpermiso_regla_octava(
-                    db=db,
-                    invoice=invoice,
-                    line=line,
-                    company_rfc=company_rfc,
-                    tenant_id=tenant_id,
-                    company_id=company_id,
-                    errors=errors,
+                    db=db, invoice=invoice, line=line, company_rfc=company_rfc,
+                    tenant_id=tenant_id, company_id=company_id, errors=errors,
                 )
                 if available is not None:
                     key = (available.octave_permit, available.ro_line, available.country_code)
@@ -137,35 +120,16 @@ def _validate_lines(
     return octave_desc, octave_available
 
 
-def _validate_sisimp_limits(
-    invoice: InvoiceHeader,
-    errors: ErrorCollector,
-) -> None:
-    """
-    Valida los límites de cantidad, peso y valor configurados en SisImp.
-
-    TODO: Leer los parámetros SisImp desde la configuración del sistema:
-          - SisImp:CantLimiteMin / SisImp:CantLimite
-          - SisImp:PesoLimiteMin / SisImp:PesoLimite
-          - SisImp:ValorLimiteMin / SisImp:ValorLimite
-    Una vez disponibles, usar invoice.financials.total_quantity, net_weight y value_mc.
-    """
-    # TODO: Implementar cuando SisImp esté disponible en la configuración del tenant
-    pass
+def _validate_sisimp_limits(invoice: InvoiceHeader, settings: dict, errors: ErrorCollector) -> None:
+    """Valida los límites de cantidad, peso y valor configurados en SisImpo/SisDef."""
+    review_limits(invoice, settings, errors)
 
 
 def _update_invoice_totals(invoice: InvoiceHeader, lines: List[LineItem]) -> None:
-    """
-    Copia los totales calculados de financials/logistics al encabezado de la factura
-    y calcula IVA, incrementables y valores de aduanas.
-
-    TODO: Validar SSisGen:ActSeguridad para asignar el usuario que actualizó.
-    TODO: Validar SSisGen:CalValBaseTCPed para registrar el mensaje de procesamiento.
-    """
+    """Actualiza totales, IVA e incrementables en la factura."""
     tc = Decimal(str(invoice.financials.exchange_rate or 0))
     tc_mm = Decimal(str(invoice.financials.exchange_rate_mm or 0))
 
-    # Calcular IVA sólo para facturas con fecha posterior al corte (78165 en Clarion =     2004-06-01 aprox.)
     iva_factor = Decimal(str(invoice.financials.iva_factor or 0)) if invoice.financials.iva_factor else Decimal(0)
     if invoice.invoice_date and invoice.invoice_date >= date(2014, 12, 31):
         invoice.financials.iva_mn = float(Decimal(str(invoice.financials.value_mn or 0)) * iva_factor / 100)
@@ -174,83 +138,93 @@ def _update_invoice_totals(invoice: InvoiceHeader, lines: List[LineItem]) -> Non
         invoice.financials.iva_mn = 0.0
         invoice.financials.iva_me = 0.0
 
-    # Calcular total de incrementables por tipo de moneda
     freight = Decimal(str(invoice.financials.freight or 0))
     insurance = Decimal(str(invoice.financials.insurance or 0))
     packaging = Decimal(str(invoice.financials.packaging or 0))
     other = Decimal(str(invoice.financials.other_increments or 0))
     base_increm = freight + insurance + packaging + other
 
-    if invoice.financials.currency == Currency.FOREIGN:  # ME
+    if invoice.financials.currency == Currency.FOREIGN:
         val_seguro = Decimal(str(invoice.financials.total_increments_me or 0)) - base_increm
         invoice.financials.total_increments_me = float(base_increm + val_seguro)
         invoice.financials.total_increments_mn = float(Decimal(str(invoice.financials.total_increments_me)) * tc)
-
-    elif invoice.financials.currency == Currency.LOCAL:  # MN
+    elif invoice.financials.currency == Currency.LOCAL:
         val_seguro = Decimal(str(invoice.financials.total_increments_mn or 0)) - base_increm
         invoice.financials.total_increments_mn = float(base_increm + val_seguro)
-        invoice.financials.total_increments_me = float(
-            (Decimal(str(invoice.financials.total_increments_mn)) / tc) if tc else Decimal(0)
-        )
-
-    elif invoice.financials.currency == Currency.MANUAL:  # MC
-        val_seguro = (
-            (Decimal(str(invoice.financials.total_increments_me or 0)) / tc_mm) if tc_mm else Decimal(0)
-        ) - base_increm
+        invoice.financials.total_increments_me = float((Decimal(str(invoice.financials.total_increments_mn)) / tc) if tc else Decimal(0))
+    elif invoice.financials.currency == Currency.MANUAL:
+        val_seguro = ((Decimal(str(invoice.financials.total_increments_me or 0)) / tc_mm) if tc_mm else Decimal(0)) - base_increm
         invoice.financials.total_increments_me = float((base_increm + val_seguro) * tc_mm)
         invoice.financials.total_increments_mn = float(Decimal(str(invoice.financials.total_increments_me)) * tc)
 
-    # Marcar la factura como procesada
     invoice.status = InvoiceStatus.PROCESSED
     invoice.party_count = len(lines)
 
-    # TODO: SSisGen:ActSeguridad = 1 → invoice.updated_by = current_user
-    # TODO: SSisGen:CalValBaseTCPed = 1 →
-    #       invoice.process_log = "Se Actualizó con el Tipo de Cambio de la Fecha de Pago de Pedimento."
+    if getattr(invoice, "_cal_val_base_tc", 0) == 1:
+        invoice.process_log = "Se Actualizó con el Tipo de Cambio de la Fecha de Pago de Pedimento."
+    if getattr(invoice, "_act_seguridad", 0) == 1 and hasattr(invoice, "_username"):
+        invoice.updated_by = invoice._username
 
 
-def main_process(db: Session, invoice: InvoiceHeader, tenant_id: str, company_id: str) -> dict:
-    """
-    Proceso principal para importar facturas.
-
-    Flujo (porta la rutina principal del legacy SCAII):
-    1. Validación previa de datos (pre_validators)
-    2. Tipo de cambio del pedimento (TODO: SSisGen:CalValBaseTCPed)
-    3. Revisión de clases, tipo de cambio y pesos
-    4. Asignación de valores por partida y totalización
-    5. Validaciones per-línea (costo, clase, número de parte, Regla Octava, UMA)
-    6. Validación de límites SisImp (TODO)
-    7. Si no hay errores: actualizar totales e incrementables en la factura y hacer commit
-    8. Si hay errores: rollback (SQLAlchemy lo maneja con la excepción)
-    """
+def main_process(db: Session, invoice: InvoiceHeader, tenant_id: str, company_id: str, username: str = "SYSTEM") -> dict:
+    """Proceso principal para importar facturas."""
     errors = ErrorCollector()
-
-    # Paso 1: Validación previa
     lines = pre_validators(db, invoice, tenant_id, company_id, errors)
     if not lines:
-        errors.add_error(
-            field="line_items",
-            message="La factura debe contener al menos una partida para ser importada",
-            solution=["Agregue partidas a la factura antes de intentar importarla"],
-            code="NO_LINE_ITEMS",
-        )
+        errors.add_error(field="line_items", message="La factura debe contener al menos una partida", solution=["Agregue partidas"], code="NO_LINE_ITEMS")
     errors.raise_if_errors()
 
-    # TODO: SSisGen:CalValBaseTCPed = 1 → obtener tipo de cambio de la fecha de pago del pedimento
-    #       y asignarlo a invoice.financials.exchange_rate antes de continuar.
-    #       invoice.which_exchange_rate = 'TCPED'  (o 'TCFAC' si CalValBaseTCPed = 0)
+    settings = AppSettingsService.get_resolved_settings(db, int(tenant_id), int(company_id))
+    
+    inv_type = (invoice.invoice_type or "").strip().upper()
+    op_type = "imp"
+    
+    # Hierarchical resolve: invoices.types.imp.{type}.ssisgen.ssimpFormData
+    inv_map = settings.get("invoices", {}).get("types", {}).get(op_type, {}).get(inv_type, {})
+    form_data = inv_map.get("ssisgen", {}).get("ssimpFormData", {}) or inv_map.get("qsisgen", {}).get("ssimpFormData", {}) or settings.get("ssisgen", {}) or settings.get("qsisgen", {})
+
+    cal_val_base_tc = int(form_data.get("calvalbasetcped") or form_data.get("CalValBaseTCPed") or 0)
+    act_seguridad = int(form_data.get("actseguridad") or form_data.get("ActSeguridad") or 0)
+    logger.info(f"AUDIT_DEBUG: act_seguridad resolve result = {act_seguridad} for Invoice={invoice.invoice_number}")
+
+    invoice._cal_val_base_tc = cal_val_base_tc
+    invoice._act_seguridad = act_seguridad
+    invoice._username = username
+
+    exchange_rate = invoice.financials.exchange_rate if invoice.financials else 0
+    which_exchange_rate = "TCFAC"
+
+    if cal_val_base_tc == 1:
+        if invoice.compliance_mx and invoice.compliance_mx.pedimento:
+            pedimento = invoice.compliance_mx.pedimento
+            if pedimento.pedimento_dates and pedimento.pedimento_dates.payment_date:
+                payment_date = pedimento.pedimento_dates.payment_date
+                from api.v1.modules.a76.general_catalogs.exchange_rate.models import ExchangeRate
+                from sqlalchemy import select
+                stmt = select(ExchangeRate).where(ExchangeRate.tenant_id == int(tenant_id), ExchangeRate.company_id == int(company_id), ExchangeRate.date == payment_date.date())
+                ex_rate_row = db.execute(stmt).scalar_one_or_none()
+                if ex_rate_row:
+                    exchange_rate = float(ex_rate_row.value)
+                    which_exchange_rate = "TCPED"
+                else:
+                    errors.add_error(field="exchange_rate", message=f"No se encontró tipo de cambio para {payment_date.date()}.", solution=["Capturar TC en catálogos."], code="EXCHANGE_RATE_NOT_FOUND")
+            else:
+                errors.add_error(field="pedimento", message="El pedimento no tiene fecha de pago.", solution=["Capturar fecha de pago."], code="PEDIMENTO_NO_PAYMENT_DATE")
+        else:
+            errors.add_error(field="compliance_mx.pedimento", message="Se requiere pedimento para el TC.", solution=["Asignar pedimento."], code="PEDIMENTO_REQUIRED_FOR_TC")
+
+    if invoice.compliance_mx: invoice.compliance_mx.which_exchange_rate = which_exchange_rate
+    if invoice.financials: invoice.financials.exchange_rate = exchange_rate
+    db.flush()
 
-    # Paso 2: Revisión de clases y fracciones
     review_classes(db, invoice, lines, tenant_id, company_id, errors)
-    review_exchange_rate(db, invoice, errors)
+    review_exchange_rate(db, invoice, cal_val_base_tc, errors)
 
     if invoice.logistics and invoice.logistics.weight_type == "kgs":
         review_weights_kgs(db, lines, tenant_id, company_id, errors)
     elif invoice.logistics and invoice.logistics.weight_type == "lbs":
         review_weights_lbs(db, lines, tenant_id, company_id, errors)    
 
-    # Paso 3: Asignación de valores por partida y totalización de factura
-    # Para IMPO DEF / Compras Mexicanas se usa la versión con IVA por partida.    
     invoice_type = (invoice.invoice_type or "").strip().upper()   
     if invoice_type in {"DEF", "MEX"}:
         assign_values_iva_lines(invoice, lines)
@@ -259,42 +233,30 @@ def main_process(db: Session, invoice: InvoiceHeader, tenant_id: str, company_id
         assign_values_lines(invoice, lines)
         assign_values_invoice(invoice, lines)
 
-    # Paso 4: Validaciones per-línea
     octave_desc, octave_available = _validate_lines(db, invoice, lines, tenant_id, company_id, errors)
-
     company = db.get(Company, invoice.company_id)
-
     if company.prosec and octave_desc:
-        valida_imp_regla_octava(
-            db=db,
-            desc_list=octave_desc,
-            dis_dict=octave_available,
-            tenant_id=tenant_id,
-            company_id=company_id,
-            errors=errors,
-        )
-
-    # Paso 5: Límites de SisImp
-    _validate_sisimp_limits(invoice, errors)
+        valida_imp_regla_octava(db=db, desc_list=octave_desc, dis_dict=octave_available, tenant_id=tenant_id, company_id=company_id, errors=errors)
 
+    _validate_sisimp_limits(invoice, settings, errors)
     errors.raise_if_errors()
 
-    # Paso 6: Descontar cupos de Regla Octava
     sql_errors: list = []
     if octave_desc:
-        descuenta_cupo_r_octava(
-            db=db,
-            desc_list=octave_desc,
-            tenant_id=tenant_id,
-            company_id=company_id,
-            sql_errors=sql_errors,
-        )
+        descuenta_cupo_r_octava(db=db, desc_list=octave_desc, tenant_id=tenant_id, company_id=company_id, sql_errors=sql_errors)
 
-    # Paso 7: Actualizar totales, IVA e incrementables y marcar como procesada
     _update_invoice_totals(invoice, lines)
-
-    # Paso 8: Generar saldos en a24.balance_movement (una entrada por partida)
     if invoice_type not in {"DEF", "MEX"}:
         create_balance_entries(db, invoice, lines)
 
-    db.flush()
\ No newline at end of file
+    db.flush()
+    if act_seguridad == 1:
+        from api.v1.modules.a76.audit_log.services.service import AuditService
+        AuditService.create_audit_log(
+            db=db, reference=invoice.invoice_number, procedure="ACTUALIZAR FACTURA", movement="IMPORTACION",
+            username=username, tenant_id=int(tenant_id), company_id=int(company_id),
+            table_name="invoice_header", record_id=str(invoice.id), operation_type="UPDATE"
+        )
+
+    db.flush()
+    return {"status": "success", "invoice_id": str(invoice.id)}
diff --git a/backend/api/v1/modules/a76/invoices/imports/process/pre_validators.py b/backend/api/v1/modules/a76/invoices/imports/process/pre_validators.py
index c1c47b7f..b15bc7fb 100644
--- a/backend/api/v1/modules/a76/invoices/imports/process/pre_validators.py
+++ b/backend/api/v1/modules/a76/invoices/imports/process/pre_validators.py
@@ -3,6 +3,7 @@ from sqlalchemy.orm import Session
 from api.v1.modules.a76.invoices.models import InvoiceHeader, InvoiceStatus
 from api.v1.modules.a76.items.models import LineItem
 from api.v1.modules.a76.general_catalogs.fractions.warning_fractions.models import WarningFraction
+from api.v1.modules.a76.app_settings.service import AppSettingsService
 from core.exceptions import ErrorCollector
 
 def pre_validators(db: Session, invoice: InvoiceHeader, tenant_id: str, company_id: str,  errors: ErrorCollector):
@@ -35,10 +36,34 @@ def pre_validators(db: Session, invoice: InvoiceHeader, tenant_id: str, company_
     if not invoice.compliance_mx.customs_broker_id:
         errors.add_required_error("compliance_mx.customs_broker_id")    
             
-    #TODO: SSISGEN: Seguridad Ejemplo en:  BrowseQFacImp 
-    
-    # 2.- Existe tipo de cambio para la factura seleccionada    
-    #TODO: SSISGEN: VALIDACION DEL TIPO DE CAMBIO EN BASE A LA FECHA DE PAGO DEL PEDIMENTO.
+    # Validación de estatus de pedimento (CERRADO / PAGADO)
+    if invoice.compliance_mx and invoice.compliance_mx.pedimento:
+        ped = invoice.compliance_mx.pedimento
+        if ped.pedimento_dates and ped.pedimento_dates.payment_date:
+            from datetime import datetime
+            today = datetime.now().date()
+            pay_date = ped.pedimento_dates.payment_date.date()
+            
+            # Obtener parámetros de seguridad
+            settings = AppSettingsService.get_resolved_settings(db, int(tenant_id), int(company_id))
+            # Revisar actseguridad en ssisgen o qsisgen (según el sistema origen)
+            gen_params = settings.get("ssisgen", {})
+            if not gen_params:
+                gen_params = settings.get("qsisgen", {})
+            
+            act_seguridad = int(gen_params.get("actseguridad", 1))
+            
+            # Si la fecha es futura (> hoy) o si la seguridad está desactivada (0), permitimos con advertencia
+            if pay_date > today or act_seguridad == 0:
+                pass # Permitir la actualización, el proceso continuará
+            else:
+                errors.add_error(
+                    field="compliance_mx.pedimento",
+                    message=f"No se puede procesar la factura porque el pedimento {ped.pedimento_number} ya se encuentra pagado el {pay_date}.",
+                    solution=["Si requiere hacer cambios, desactive 'Solicitar Autorización para Actualizar Facturas' en la configuración general o rectifique el pedimento."],
+                    code="PEDIMENTO_ALREADY_PAID"
+                )
+                errors.raise_if_errors()
     
     
     if not invoice.financials.exchange_rate or invoice.financials.exchange_rate <= 0:
diff --git a/backend/api/v1/modules/a76/invoices/imports/process/sub_process/review_exchange_rate.py b/backend/api/v1/modules/a76/invoices/imports/process/sub_process/review_exchange_rate.py
index 892fa2d7..0ab291a7 100644
--- a/backend/api/v1/modules/a76/invoices/imports/process/sub_process/review_exchange_rate.py
+++ b/backend/api/v1/modules/a76/invoices/imports/process/sub_process/review_exchange_rate.py
@@ -11,6 +11,7 @@ from core.exceptions import ErrorCollector
 def review_exchange_rate(
     db: Session,
     invoice: InvoiceHeader,
+    cal_val_base_tc: int,
     errors: ErrorCollector,
 ) -> None:
     """
@@ -19,10 +20,11 @@ def review_exchange_rate(
 
     Ported from legacy REVISA_TIPOCAMBIO routine.
     Only runs when the system is NOT configured to use the pedimento's exchange
-    rate (SisGen:CalValBaseTCPed = 0), which corresponds to the TODO comment in
-    main_process: the caller is responsible for skipping this call when that flag
-    is active.
+    rate (SisGen:CalValBaseTCPed = 0).
     """
+    if cal_val_base_tc == 1:
+        # SKIP: TC is derived from pedimento payment date
+        return
     if not invoice.invoice_date:
         return
 
diff --git a/backend/api/v1/modules/a76/invoices/imports/process/sub_process/review_limits.py b/backend/api/v1/modules/a76/invoices/imports/process/sub_process/review_limits.py
new file mode 100644
index 00000000..6e100527
--- /dev/null
+++ b/backend/api/v1/modules/a76/invoices/imports/process/sub_process/review_limits.py
@@ -0,0 +1,80 @@
+import logging
+from decimal import Decimal
+from typing import Dict, Any, Optional
+from api.v1.modules.a76.invoices.models import InvoiceHeader
+from core.exceptions import ErrorCollector
+
+logger = logging.getLogger(__name__)
+
+def review_limits(
+    invoice: InvoiceHeader,
+    settings: Dict[str, Any],
+    errors: ErrorCollector
+) -> None:
+    """
+    Valida que los totales de la factura no excedan los límites configurados 
+    en SisImpo o SisDef.
+    """
+    if not invoice.financials:
+        logger.warning(f"LIMIT_CHECK: No financials found for invoice {invoice.id}")
+        return
+
+    # Determinamos qué categoría de parámetros usar según el tipo de factura
+    invoice_type = (invoice.invoice_type or "").strip().upper()
+    op_type = "imp" # Por ahora enfocado en importación
+
+    # 1. Intentar obtener de la raíz (ssisimpo/ssisdef)
+    if invoice_type in {"DEF", "MEX"}:
+        params = settings.get("ssisdef", {})
+        cat_name = "ssisdef"
+    else:
+        params = settings.get("ssisimpo", {})
+        cat_name = "ssisimpo"
+
+    # 2. Si no están en la raíz, intentar en la estructura profunda (invoices.types...)
+    # Esta es la estructura que viene del frontend según el JSON "hermoso"
+    if not params.get("CantLimite") and not params.get("cantlimite"):
+        invoice_map = settings.get("invoices", {}).get("types", {}).get(op_type, {}).get(invoice_type, {})
+        # Buscar en ssimpFormData dentro de qsisgen o ssisgen
+        params = invoice_map.get("qsisgen", {}).get("ssimpFormData", {}) or invoice_map.get("ssisgen", {}).get("ssimpFormData", {}) or params
+        cat_name = f"invoices.types.{op_type}.{invoice_type}.ssimpFormData"
+
+    # Obtener límites Máximos
+    limit_qty = Decimal(str(params.get("cantlimite") or params.get("CantLimite") or 0))
+    limit_weight = Decimal(str(params.get("pesolimite") or params.get("PesoLimite") or 0))
+    limit_value = Decimal(str(params.get("valorlimite") or params.get("ValorLimite") or 0))
+
+    # Obtener límites Mínimos
+    min_limit_qty = Decimal(str(params.get("cantlimitemin") or params.get("CantLimiteMin") or 0))
+    min_limit_weight = Decimal(str(params.get("pesolimitemin") or params.get("PesoLimiteMin") or 0))
+    min_limit_value = Decimal(str(params.get("valorlimitemin") or params.get("ValorLimiteMin") or 0))
+
+    # Totales actuales de la factura
+    current_qty = Decimal(str(invoice.financials.total_quantity or 0))
+    current_weight = Decimal(str(invoice.financials.net_weight or 0))
+    current_value = Decimal(str(invoice.financials.value_me or 0))
+
+    logger.info(f"LIMIT_CHECK: Invoice={invoice.invoice_number} Type={invoice_type} Cat={cat_name}")
+    logger.info(f"LIMIT_CHECK: Qty: Current={current_qty} Max={limit_qty} Min={min_limit_qty}")
+    logger.info(f"LIMIT_CHECK: Weight: Current={current_weight} Max={limit_weight} Min={min_limit_weight}")
+    logger.info(f"LIMIT_CHECK: Value: Current={current_value} Max={limit_value} Min={min_limit_value}")
+
+    # --- Validaciones de Máximos ---
+    if limit_qty > 0 and current_qty > limit_qty:
+        errors.add_error(field="financials.total_quantity", message=f"La cantidad total ({current_qty}) excede el máximo permitido ({limit_qty}).", solution=["Ajuste las cantidades."], code="LIMIT_QTY_EXCEEDED")
+
+    if limit_weight > 0 and current_weight > limit_weight:
+        errors.add_error(field="financials.net_weight", message=f"El peso neto total ({current_weight}) excede el máximo permitido ({limit_weight}).", solution=["Ajuste los pesos."], code="LIMIT_WEIGHT_EXCEEDED")
+
+    if limit_value > 0 and current_value > limit_value:
+        errors.add_error(field="financials.value_me", message=f"El valor total en USD ({current_value}) excede el máximo permitido ({limit_value}).", solution=["Ajuste los costos."], code="LIMIT_VALUE_EXCEEDED")
+
+    # --- Validaciones de Mínimos ---
+    if min_limit_qty > 0 and current_qty < min_limit_qty:
+        errors.add_error(field="financials.total_quantity", message=f"La cantidad total ({current_qty}) es inferior al mínimo requerido ({min_limit_qty}).", solution=["Aumente las cantidades."], code="MIN_LIMIT_QTY_NOT_MET")
+
+    if min_limit_weight > 0 and current_weight < min_limit_weight:
+        errors.add_error(field="financials.net_weight", message=f"El peso neto total ({current_weight}) es inferior al mínimo requerido ({min_limit_weight}).", solution=["Aumente los pesos."], code="MIN_LIMIT_WEIGHT_NOT_MET")
+
+    if min_limit_value > 0 and current_value < min_limit_value:
+        errors.add_error(field="financials.value_me", message=f"El valor total en USD ({current_value}) es inferior al mínimo requerido ({min_limit_value}).", solution=["Aumente los costos."], code="MIN_LIMIT_VALUE_NOT_MET")
diff --git a/backend/api/v1/modules/a76/invoices/imports/process/sub_process/review_series.py b/backend/api/v1/modules/a76/invoices/imports/process/sub_process/review_series.py
index 9ccdd84f..1e5de35d 100644
--- a/backend/api/v1/modules/a76/invoices/imports/process/sub_process/review_series.py
+++ b/backend/api/v1/modules/a76/invoices/imports/process/sub_process/review_series.py
@@ -6,12 +6,9 @@ from api.v1.modules.a76.general_catalogs.company.models import Company
 from api.v1.modules.a76.general_catalogs.units_of_measure.models import UnitOfMeasure
 from api.v1.modules.a76.items.models import LineItem
 from api.v1.modules.a76.items.series.models import Serie
+from api.v1.modules.a76.app_settings.service import AppSettingsService
 from core.exceptions import ErrorCollector
 
-# Clarion: SisGen:CantvsCantSeries
-# TODO: leer desde configuración del tenant cuando SisGen esté disponible
-_SISIMP_CANT_VS_CANT_SERIES: int = 0  # 0 = desactivado
-
 # RFCs donde la validación de cantidad vs series únicamente aplica a PZA (paridad Clarion)
 _RFC_EXCEPCION_PZA = {
     "IMS030409FZ0",
@@ -24,7 +21,9 @@ _RFC_EXCEPCION_PZA = {
 def review_series(
     db: Session,
     line: LineItem,    
-    company_rfc: int,
+    company_rfc: str,
+    tenant_id: str,
+    company_id: str,
     errors: ErrorCollector,
 ) -> None:
     """
@@ -64,8 +63,13 @@ def review_series(
         return
 
     # GNiv:CantSerievsCant = 0 → el bloque series > cantidad estaba comentado en Clarion original
-    # TODO: leer SisGen:CantvsCantSeries desde la configuración del tenant
-    if _SISIMP_CANT_VS_CANT_SERIES != 1:
+    settings = AppSettingsService.get_resolved_settings(db, int(tenant_id), int(company_id))
+    q_gen = settings.get("qsisgen", {})
+    s_gen = settings.get("ssisgen", {})
+    
+    valida_cant_series = int(q_gen.get("cantvscantseries") or s_gen.get("cantvscantseries", 0))
+
+    if valida_cant_series != 1:
         return
 
     qty = line.quantity.quantity if line.quantity else None
diff --git a/backend/api/v1/modules/a76/invoices/imports/process/task.py b/backend/api/v1/modules/a76/invoices/imports/process/task.py
index 4ca0360f..1cabe600 100644
--- a/backend/api/v1/modules/a76/invoices/imports/process/task.py
+++ b/backend/api/v1/modules/a76/invoices/imports/process/task.py
@@ -4,22 +4,10 @@ from celery import Task
 
 from core.celery_app import celery_app
 from core.database import CoreSessionLocal
-from core.exceptions import ErrorCollector, ValidationException
+from core.exceptions import ValidationException
 
 from api.v1.modules.a76.invoices.models import InvoiceHeader
-from api.v1.modules.a76.general_catalogs.company.models import Company
-from .pre_validators import pre_validators
-from .sub_process.review_classes import review_classes
-from .sub_process.review_exchange_rate import review_exchange_rate
-from .sub_process.review_weights import review_weights_kgs, review_weights_lbs
-from .sub_process.review_rule_octave import valida_imp_regla_octava, descuenta_cupo_r_octava
-from .sub_process.assing_values import assign_values_lines, assign_values_invoice
-from .sub_process.assing_values_def_mex import (
-    assign_values_iva_lines,
-    assign_values_invoice_totals,
-)
-from ..balance.create_balance_entries import create_balance_entries
-from .main_process import _validate_sisimp_limits, _update_invoice_totals, _validate_lines
+from .main_process import main_process
 
 logger = logging.getLogger(__name__)
 
@@ -29,7 +17,7 @@ def _progress(task: Task, current: int, status: str) -> None:
 
 
 @celery_app.task(bind=True, name="process_invoice_task")
-def process_invoice_task(self: Task, invoice_id: int, tenant_id: str, company_id: str) -> dict:
+def process_invoice_task(self: Task, invoice_id: int, tenant_id: str, company_id: str, username: str = "SYSTEM") -> dict:
     """
     Procesa una factura de importación ejecutando todas las validaciones y
     actualizaciones del proceso principal (main_process) con reporte de progreso.
@@ -46,95 +34,23 @@ def process_invoice_task(self: Task, invoice_id: int, tenant_id: str, company_id
                 "errors": [],
             }
 
-        errors = ErrorCollector()
-
-        # ── Paso 2: Pre-validaciones ──────────────────────────────────────────
-        _progress(self, 10, "Validando datos de la factura...")
-        lines = pre_validators(db, invoice, tenant_id, company_id, errors)
-        if not lines:
-            errors.add_error(
-                field="line_items",
-                message="La factura debe contener al menos una partida para ser importada",
-                solution=["Agregue partidas a la factura antes de intentar importarla"],
-                code="NO_LINE_ITEMS",
-            )
-        errors.raise_if_errors()
-
-        # ── Paso 3: Revisión clases, tipo de cambio y pesos ──────────────────
-        _progress(self, 30, "Revisando clases y tipo de cambio...")
-        review_classes(db, invoice, lines, tenant_id, company_id, errors)
-        review_exchange_rate(db, invoice, errors)
-
-        if invoice.logistics and invoice.logistics.weight_type == "kgs":
-            review_weights_kgs(db, lines, tenant_id, company_id, errors)
-        elif invoice.logistics and invoice.logistics.weight_type == "lbs":
-            review_weights_lbs(db, lines, tenant_id, company_id, errors)
-
-        # ── Paso 4: Asignación de valores ─────────────────────────────────────
-        _progress(self, 50, "Calculando valores por partida...")
-        raw_type = invoice.invoice_type
-        invoice_type = (raw_type or "").strip().upper()
-        logger.info(
-            "celery import process invoice_type: invoice_id=%s raw=%r normalized=%r document_type=%r",
-            invoice.id,
-            raw_type,
-            invoice_type,
-            getattr(invoice, "document_type", None),
-        )
-        if invoice_type in {"DEF", "MEX"}:
-            assign_values_iva_lines(invoice, lines)
-            assign_values_invoice_totals(invoice, lines)
-        else:
-            assign_values_lines(invoice, lines)
-            assign_values_invoice(invoice, lines)
-
-        # ── Paso 5: Validaciones por partida ──────────────────────────────────
-        _progress(self, 70, "Validando partidas...")
-        octave_desc, octave_available = _validate_lines(
-            db, invoice, lines, tenant_id, company_id, errors
+        # ── Paso 2: Ejecutar Proceso Principal ───────────────────────────────
+        # Unificamos lógica: El task solo llama al main_process centralizado.
+        _progress(self, 20, "Iniciando procesamiento de factura...")
+        result = main_process(
+            db=db, 
+            invoice=invoice, 
+            tenant_id=tenant_id, 
+            company_id=company_id, 
+            username=username
         )
 
-        # ── Paso 6: Regla Octava y límites SisImp ─────────────────────────────
-        _progress(self, 85, "Validando cupos de Regla Octava...")
-        company: Company | None = db.get(Company, invoice.company_id)
-        if company and company.prosec and octave_desc:
-            valida_imp_regla_octava(
-                db=db,
-                desc_list=octave_desc,
-                dis_dict=octave_available,
-                tenant_id=tenant_id,
-                company_id=company_id,
-                errors=errors,
-            )
-        _validate_sisimp_limits(invoice, errors)
-        errors.raise_if_errors()
-
-        # ── Paso 7: Descuento de cupos y actualización de totales ─────────────
-        _progress(self, 95, "Actualizando totales...")
-        sql_errors: list = []
-        if octave_desc:
-            descuenta_cupo_r_octava(
-                db=db,
-                desc_list=octave_desc,
-                tenant_id=tenant_id,
-                company_id=company_id,
-                sql_errors=sql_errors,
-            )
-        _update_invoice_totals(invoice, lines)
-
-        # ── Paso 8: Generar saldos en a24.balance_movement ───────────────────
-        _progress(self, 98, "Generando saldos de inventario...")
-        if invoice_type not in {"DEF", "MEX"}:
-            create_balance_entries(db, invoice, lines)
-
-        db.flush()
+        # ── Paso 3: Confirmar transacción ─────────────────────────────────────
+        _progress(self, 95, "Confirmando cambios...")
         db.commit()
-
-        return {
-            "status": "success",
-            "invoice_id": invoice_id,
-            "sql_errors": sql_errors,
-        }
+        
+        _progress(self, 100, "Proceso completado.")
+        return result
 
     except ValidationException as exc:
         db.rollback()
@@ -145,6 +61,7 @@ def process_invoice_task(self: Task, invoice_id: int, tenant_id: str, company_id
         }
     except Exception as exc:
         db.rollback()
+        logger.error(f"Error en process_invoice_task: {str(exc)}", exc_info=True)
         raise exc
     finally:
         db.close()
diff --git a/backend/api/v1/modules/a76/invoices/imports/revert/main_process.py b/backend/api/v1/modules/a76/invoices/imports/revert/main_process.py
index 3b1824ff..fd10f2d5 100644
--- a/backend/api/v1/modules/a76/invoices/imports/revert/main_process.py
+++ b/backend/api/v1/modules/a76/invoices/imports/revert/main_process.py
@@ -1,3 +1,4 @@
+from api.v1.modules.a76.app_settings.service import AppSettingsService
 from decimal import Decimal
 from typing import List
 
@@ -20,7 +21,7 @@ def _validate_returned_quantities(
     db: Session,
     invoice: InvoiceHeader,
     lines: List[LineItem],
-    errors: ErrorCollector,
+    errors: ErrorCollector, cancelled_by: str = "SYSTEM",
 ) -> None:
     """
     Verifica que ninguna partida tenga saldos pendientes por exportaciones
@@ -162,7 +163,7 @@ def revert_process(
     lines: List[LineItem],
     tenant_id: str,
     company_id: str,
-    errors: ErrorCollector,
+    errors: ErrorCollector, cancelled_by: str = "SYSTEM",
 ) -> list:
     """
     Proceso principal de des-actualización de una factura de importación
@@ -210,4 +211,19 @@ def revert_process(
     # activos (ya validado arriba, pero se mantiene como doble seguro).
     void_balance_entries(db, invoice)
 
+    
+    # Auditoría de Desactualización
+    settings = AppSettingsService.get_resolved_settings(db, int(tenant_id), int(company_id))
+    q_gen = settings.get("qsisgen", {})
+    s_gen = settings.get("ssisgen", {})
+    act_seguridad = int(q_gen.get("actseguridad") or s_gen.get("actseguridad") or q_gen.get("ActSeguridad") or s_gen.get("ActSeguridad", 0))
+    
+    if act_seguridad == 1:
+        from api.v1.modules.a76.audit_log.services.service import AuditService
+        AuditService.create_audit_log(
+            db=db, reference=invoice.invoice_number, procedure="ANULAR FACTURA", movement="DESACTUALIZACION",
+            username=cancelled_by or "SYSTEM", tenant_id=int(tenant_id), company_id=int(company_id),
+            table_name="invoice_header", record_id=str(invoice.id), operation_type="UPDATE"
+        )
+    
     return sql_errors
diff --git a/backend/api/v1/modules/a76/items/exports/validators/common.py b/backend/api/v1/modules/a76/items/exports/validators/common.py
index 0012e7bf..579ae7d8 100644
--- a/backend/api/v1/modules/a76/items/exports/validators/common.py
+++ b/backend/api/v1/modules/a76/items/exports/validators/common.py
@@ -1,6 +1,6 @@
 from sqlalchemy import exists
 from sqlalchemy.orm import Session
-from api.v1.modules.a76.invoices.common.common_validators import invoice_exists_by_id
+from api.v1.modules.a76.invoices.common.common_validators import invoice_id_required
 from core.exceptions import ErrorCollector
 from sqlalchemy import func
 
@@ -32,7 +32,7 @@ def validate_common(
     errors: ErrorCollector,
     line_number: int,
 ):
-    invoice: InvoiceHeader = invoice_exists_by_id(
+    invoice: InvoiceHeader = invoice_id_required(
         db, line.invoice_id, tenant_id, company_id, errors
     )
     line_item: LineItem = item_exists(db, line.line_number, tenant_id, company_id)
diff --git a/backend/api/v1/modules/a76/items/exports/validators/create.py b/backend/api/v1/modules/a76/items/exports/validators/create.py
index 37efc39d..0e5792fc 100644
--- a/backend/api/v1/modules/a76/items/exports/validators/create.py
+++ b/backend/api/v1/modules/a76/items/exports/validators/create.py
@@ -53,8 +53,16 @@ def validate_create(
     if not line.class_id:
         errors.add_required_error(field=f"line[{line_number}].class_id")
 
-    if not line.quantity or not line.quantity.quantity or line.quantity.quantity <= 0:
+    if not line.quantity or line.quantity.quantity is None:
         errors.add_required_error(field=f"line[{line_number}].quantity.quantity")
+    elif line.quantity.quantity <= 0:
+        errors.add_error(
+            field=f"line[{line_number}].quantity.quantity",
+            message=f"La cantidad debe ser mayor a cero (recibido: {line.quantity.quantity})",
+            solution=["Capturar una cantidad válida mayor a cero."],
+            code="INVALID_QUANTITY",
+            value=float(line.quantity.quantity)
+        )
 
     # TODO: Añadir validacion SSisGen:CalcularCostoUnitarioEnBaseAValorTotalScaf <-- de la tabla de preferencias de el sistema
     # if SSisGen:CalcularCostoUnitarioEnBaseAValorTotalScaf == False:
@@ -68,8 +76,16 @@ def validate_create(
                 field=f"line[{line_number}].financial.unit_cost_capture"
             )
 
-    if not line.quantity or not line.quantity.net_weight or line.quantity.net_weight <= 0:
+    if not line.quantity or line.quantity.net_weight is None:
         errors.add_required_error(field=f"line[{line_number}].quantity.net_weight")
+    elif line.quantity.net_weight <= 0:
+        errors.add_error(
+            field=f"line[{line_number}].quantity.net_weight",
+            message=f"El peso neto debe ser mayor a cero (recibido: {line.quantity.net_weight})",
+            solution=["Capturar un peso neto válido mayor a cero."],
+            code="INVALID_NET_WEIGHT",
+            value=float(line.quantity.net_weight)
+        )
 
     if not line.customs or not line.customs.origin_country:
         errors.add_required_error(field=f"line[{line_number}].customs.origin_country")
diff --git a/backend/api/v1/modules/a76/items/exports/validators/update.py b/backend/api/v1/modules/a76/items/exports/validators/update.py
index bee0f84a..3d464082 100644
--- a/backend/api/v1/modules/a76/items/exports/validators/update.py
+++ b/backend/api/v1/modules/a76/items/exports/validators/update.py
@@ -184,28 +184,28 @@ def validate_update(
             line.order = existing_line.order
 
         # Descripciones
-        if not line.description.description_spanish:
+        if line.description.description_spanish is None:
             line.description.description_spanish = (
                 existing_line.description.description_spanish
             )
 
-        if not line.description.description_english:
+        if line.description.description_english is None:
             line.description.description_english = (
                 existing_line.description.description_english
             )
 
-        if not line.description.extra_description:
+        if line.description.extra_description is None:
             line.description.extra_description = (
                 existing_line.description.extra_description
             )
 
         # Marca y modelo
-        if line.description.brand:
+        if line.description.brand is not None:
             line.description.brand = line.description.brand.upper().strip()
         else:
             line.description.brand = existing_line.description.brand
 
-        if line.description.model:
+        if line.description.model is not None:
             line.description.model = line.description.model.upper().strip()
         else:
             line.description.model = existing_line.description.model
diff --git a/backend/api/v1/modules/a76/items/imports/validators/calculations.py b/backend/api/v1/modules/a76/items/imports/validators/calculations.py
index dcf97d16..f6532ebb 100644
--- a/backend/api/v1/modules/a76/items/imports/validators/calculations.py
+++ b/backend/api/v1/modules/a76/items/imports/validators/calculations.py
@@ -81,6 +81,11 @@ def calculate_values(
         return
 
     currency, currency_type, exchange_rate = result
+    
+    # Safety guard: Ensure nested objects exist before calculating
+    if not line.financial or not line.quantity:
+        return
+        
     # Prioridad: currency_type para alinear con create.py y CSV
     if currency_type in ("USD", "ME"):
         currency = "foreign"
diff --git a/backend/api/v1/modules/a76/items/imports/validators/common.py b/backend/api/v1/modules/a76/items/imports/validators/common.py
index f4c3b6ba..421e6316 100644
--- a/backend/api/v1/modules/a76/items/imports/validators/common.py
+++ b/backend/api/v1/modules/a76/items/imports/validators/common.py
@@ -1,6 +1,6 @@
 from sqlalchemy import exists
 from sqlalchemy.orm import Session
-from api.v1.modules.a76.invoices.common.common_validators import invoice_exists_by_id
+from api.v1.modules.a76.invoices.common.common_validators import invoice_id_required
 from api.v1.modules.a76.items.imports.validators.calculations import apply_calculations
 from core.exceptions import ErrorCollector
 from sqlalchemy import func
@@ -36,7 +36,7 @@ def validate_common(
     errors: ErrorCollector,
     line_number: int,
 ):
-    invoice: InvoiceHeader = invoice_exists_by_id(
+    invoice: InvoiceHeader = invoice_id_required(
         db, line.invoice_id, tenant_id, company_id, errors
     )
     line_item: LineItem = item_exists(db, line.line_number, tenant_id, company_id)
diff --git a/backend/api/v1/modules/a76/items/imports/validators/create.py b/backend/api/v1/modules/a76/items/imports/validators/create.py
index d24969fa..35b20bae 100644
--- a/backend/api/v1/modules/a76/items/imports/validators/create.py
+++ b/backend/api/v1/modules/a76/items/imports/validators/create.py
@@ -52,8 +52,16 @@ def validate_create(
     if not line.class_id:
         errors.add_required_error(field=f"line[{line_number}].class_id")
 
-    if not line.quantity or not line.quantity.quantity or line.quantity.quantity <= 0:
+    if not line.quantity or line.quantity.quantity is None:
         errors.add_required_error(field=f"line[{line_number}].quantity.quantity")
+    elif line.quantity.quantity <= 0:
+        errors.add_error(
+            field=f"line[{line_number}].quantity.quantity",
+            message=f"La cantidad debe ser mayor a cero (recibido: {line.quantity.quantity})",
+            solution=["Capturar una cantidad válida mayor a cero."],
+            code="INVALID_QUANTITY",
+            value=float(line.quantity.quantity)
+        )
 
     # TODO: Añadir validacion SSisGen:CalcularCostoUnitarioEnBaseAValorTotalScaf <-- de la tabla de preferencias de el sistema
     # if SSisGen:CalcularCostoUnitarioEnBaseAValorTotalScaf == False:
@@ -67,8 +75,16 @@ def validate_create(
                 field=f"line[{line_number}].financial.unit_cost_capture"
             )
 
-    if not line.quantity or not line.quantity.net_weight or line.quantity.net_weight <= 0:
+    if not line.quantity or line.quantity.net_weight is None:
         errors.add_required_error(field=f"line[{line_number}].quantity.net_weight")
+    elif line.quantity.net_weight <= 0:
+        errors.add_error(
+            field=f"line[{line_number}].quantity.net_weight",
+            message=f"El peso neto debe ser mayor a cero (recibido: {line.quantity.net_weight})",
+            solution=["Capturar un peso neto válido mayor a cero."],
+            code="INVALID_NET_WEIGHT",
+            value=float(line.quantity.net_weight)
+        )
 
     if not line.customs or not line.customs.origin_country:
         errors.add_required_error(field=f"line[{line_number}].customs.origin_country")
diff --git a/backend/api/v1/modules/a76/items/imports/validators/update.py b/backend/api/v1/modules/a76/items/imports/validators/update.py
index 93152823..f6dbbdc6 100644
--- a/backend/api/v1/modules/a76/items/imports/validators/update.py
+++ b/backend/api/v1/modules/a76/items/imports/validators/update.py
@@ -183,35 +183,51 @@ def validate_update(
             line.order = existing_line.order
 
         # Descripciones
-        if not line.description.description_spanish:
+        if line.description.description_spanish is None:
             line.description.description_spanish = (
                 existing_line.description.description_spanish
             )
 
-        if not line.description.description_english:
+        if line.description.description_english is None:
             line.description.description_english = (
                 existing_line.description.description_english
             )
 
-        if not line.description.extra_description:
+        if line.description.extra_description is None:
             line.description.extra_description = (
                 existing_line.description.extra_description
             )
 
-        # Marca y modelo
-        if line.description.brand:
+        # Brand and model
+        if line.description.brand is not None:
             line.description.brand = line.description.brand.upper().strip()
         else:
             line.description.brand = existing_line.description.brand
 
-        if line.description.model:
+        if line.description.model is not None:
             line.description.model = line.description.model.upper().strip()
         else:
             line.description.model = existing_line.description.model
 
-        # Subpartidas (si aplica)
-        # TODO: Implementar lógica de subpartidas si Loc:LevantarSubpartidas = 'S'    
+        # --- Resolve Settings for inherited parameters ---
+        from api.v1.modules.a76.app_settings.service import AppSettingsService
+        settings = AppSettingsService.get_resolved_settings(db, tenant_id, company_id)
         
+        inv_type = (invoice.invoice_type or "").strip().upper()
+        op_type = (invoice.operation_type or "").strip().lower() # 'imp' or 'exp'
+        
+        # Helper to get nested value from invoices.types.{op}.{type}.ssisgen.ssimpFormData
+        inv_map = settings.get("invoices", {}).get("types", {}).get(op_type, {}).get(inv_type, {})
+        # Prefeir ssisgen for this type, then qsisgen, then root ssimpo
+        form_data = inv_map.get("ssisgen", {}).get("ssimpFormData", {}) or inv_map.get("qsisgen", {}).get("ssimpFormData", {}) or settings.get("ssimpo", {})
+
+        # Subpartidas (si aplica)
+        # Clarion: LOC:LevantarSubpartidas = S
+        levantar_sub = bool(form_data.get("levantar_subpartidas") or form_data.get("LevantarSubpartidas") or False)
+        if levantar_sub:
+            # TODO: Add specific sub-item validation if needed (e.g. parent_line mandatory if it's a subpartida)
+            # Currently we just ensure the field is carried over if not provided
+            pass
 
         # Número de parte
         if not line.part_number_id:
@@ -229,7 +245,9 @@ def validate_update(
         if not line.valuation_method:
             if existing_line.valuation_method:
                 line.valuation_method = existing_line.valuation_method
-            # else: TODO: Tomar de SisImp:MetValor (preferencias del sistema)
+            else:
+                # Tomar de SisImp/SisDef:MetValor (preferencias del sistema)
+                line.valuation_method = form_data.get("metvalor") or form_data.get("MetValor")
 
         # Número de entrada
         if not line.description.entry_number:
diff --git a/backend/api/v1/modules/a76/items/models.py b/backend/api/v1/modules/a76/items/models.py
index 514da30b..6628b672 100644
--- a/backend/api/v1/modules/a76/items/models.py
+++ b/backend/api/v1/modules/a76/items/models.py
@@ -14,7 +14,6 @@ from core.database import Base
 
 from api.v1.modules.a76.classes.models import Class
 from api.v1.modules.a76.general_catalogs.units_of_measure.models import UnitOfMeasure
-from api.v1.modules.a76.general_catalogs.identifiers.models import IdentifierDetail
 
 if TYPE_CHECKING:
     from .line_financials.models import LineFinancial
@@ -22,8 +21,6 @@ if TYPE_CHECKING:
     from .line_customs.models import LineCustom
     from .line_descriptions.models import LineDescription
     from .line_references.models import LineReference
-    from api.v1.modules.a24.fa.fa_item_lines.models import FaLineItem
-    from api.v1.modules.a76.parts.models import Part
     from api.v1.modules.a76.invoices.models import InvoiceHeader
 
 
@@ -222,7 +219,7 @@ class LineItem(Base, TenantScopedMixin, TimestampMixin):
         uselist=False,
     )
     identifiers: Mapped[List["IdentifierDetail"]] = relationship(
-        IdentifierDetail,
+        "IdentifierDetail",
         back_populates="line",
         cascade="all, delete-orphan",
     )
@@ -231,6 +228,11 @@ class LineItem(Base, TenantScopedMixin, TimestampMixin):
         foreign_keys=[part_number_id],
         viewonly=True,
     )
+    component_part_info: Mapped[Optional["Part"]] = relationship(
+        "Part",
+        foreign_keys=[component_part_number_id],
+        viewonly=True,
+    )
 
 
 # ============================================================================
@@ -387,3 +389,14 @@ MIGRATION STRATEGY FROM ORIGINAL TABLES TO NORMALIZED SCHEMA:
    )
    ```
 """
+# ============================================================================
+# RUNTIME IMPORTS FOR MAPPER RESOLUTION
+# ============================================================================
+# We import these specialized models at the bottom to ensure they are registered
+# in the SQLAlchemy metadata for relationship resolution while avoiding 
+# circular import issues in the module head.
+
+from api.v1.modules.a24.fa.fa_item_lines.models import FaLineItem
+from api.v1.modules.a76.parts.models import Part
+from api.v1.modules.a76.items.series.models import Serie
+from api.v1.modules.a76.general_catalogs.identifiers.models import IdentifierDetail
diff --git a/backend/api/v1/modules/a76/items/routes.py b/backend/api/v1/modules/a76/items/routes.py
index 3f8fb8a8..a1b58388 100644
--- a/backend/api/v1/modules/a76/items/routes.py
+++ b/backend/api/v1/modules/a76/items/routes.py
@@ -44,7 +44,7 @@ async def create_item(
     - Each LineItem has one LineReference
     """
     tenant_id = validate_access_to_resource(db, company_id, current_user)
-
+    
     service = ItemService()
     return service.create(db, item_data, tenant_id, company_id)
 
diff --git a/backend/api/v1/modules/a76/items/schemas.py b/backend/api/v1/modules/a76/items/schemas.py
index 099a8571..a1383768 100644
--- a/backend/api/v1/modules/a76/items/schemas.py
+++ b/backend/api/v1/modules/a76/items/schemas.py
@@ -290,13 +290,15 @@ class LineItemResponse(LineItemBase):
 
     # Part identification
     part_number_id: Optional[int] = Field(
-        None, alias="part_number", serialization_alias="part_number_id"
+        None, alias="part_number_id_input", serialization_alias="part_number_id"
     )
+    part_number: Optional[str] = None
     component_part_number_id: Optional[int] = Field(
         None,
-        alias="component_part_number",
+        alias="component_part_number_id_input",
         serialization_alias="component_part_number_id",
     )
+    component_part_number: Optional[str] = None
     class_id: Optional[int] = None
 
     # Nested data
@@ -325,33 +327,65 @@ class LineItemResponse(LineItemBase):
     @model_validator(mode="before")
     @classmethod
     def extract_relationship_info(cls, data: Any) -> Any:
-        """Extract class_code, class_description and unit_of_measure_code from relationships"""
+        """Extract information from joined relationships to provide flat mapping for UI."""
         if isinstance(data, dict):
+            # If already a dict, ensure description syncs to top-level if missing
+            desc = data.get("description", {})
+            if isinstance(desc, dict):
+                if not data.get("part_description_es"):
+                    data["part_description_es"] = desc.get("description_spanish")
+                if not data.get("part_description_en"):
+                    data["part_description_en"] = desc.get("description_english")
             return data
 
         # It's an ORM object
         result = {}
-        for key in cls.model_fields.keys():
-            if hasattr(data, key):
-                result[key] = getattr(data, key)
+        
+        # 1. Start with model attributes (columns)
+        if hasattr(data, "__table__"):
+            for k in data.__table__.columns.keys():
+                result[k] = getattr(data, k, None)
+        else:
+            # Fallback for non-table objects if any
+            for k, v in data.__dict__.items():
+                if not k.startswith("_"):
+                    result[k] = v
 
-        # Map model field names to schema field names for aliased fields
-        if hasattr(data, "part_number"):
-            result["part_number_id"] = data.part_number
-        if hasattr(data, "component_part_number"):
-            result["component_part_number_id"] = data.component_part_number
+        # Alias mapping for part numbers
+        if hasattr(data, "part_number_id") and "part_number_id" not in result:
+            result["part_number_id"] = data.part_number_id
+        if hasattr(data, "component_part_number_id") and "component_part_number_id" not in result:
+            result["component_part_number_id"] = data.component_part_number_id
+
+        # Extract part info (string part numbers) from relationship objects
+        if hasattr(data, "part_info") and data.part_info is not None:
+            result["part_number"] = getattr(data.part_info, "part_number", None)
+        if hasattr(data, "component_part_info") and data.component_part_info is not None:
+            result["component_part_number"] = getattr(data.component_part_info, "part_number", None)
 
         # Extract class info
         if hasattr(data, "class_info") and data.class_info is not None:
-            result["class_code"] = data.class_info.class_code
-            result["class_description"] = data.class_info.description_es
+            result["class_code"] = getattr(data.class_info, "class_code", None)
+            result["class_description"] = getattr(data.class_info, "description_es", None)
 
         # Extract unit of measure code
-        if (
-            hasattr(data, "unit_of_measure_info")
-            and data.unit_of_measure_info is not None
-        ):
-            result["unit_of_measure_code"] = data.unit_of_measure_info.code
+        if hasattr(data, "unit_of_measure_info") and data.unit_of_measure_info is not None:
+            result["unit_of_measure_code"] = getattr(data.unit_of_measure_info, "code", None)
+
+        # 2. Extract nested objects and populate redundant descriptions
+        # We MUST use explicit getattr for relationships to ensure SQLAlchemy loads/uses joined-loaded ones
+        for key in ["financial", "quantity", "customs", "description", "reference", "fa_data", "series", "identifiers"]:
+            val = getattr(data, key, None)
+            if val is not None:
+                result[key] = val
+                # Sync to top-level for description redundancy (huge boost for UI stability)
+                if key == "description":
+                    result["part_description_es"] = getattr(val, "description_spanish", None)
+                    result["part_description_en"] = getattr(val, "description_english", None)
+            else:
+                # Provide default empty dict for core containers to help frontend
+                if key in ["financial", "quantity", "customs", "description"]:
+                    result[key] = {}
 
         return result
 
diff --git a/backend/api/v1/modules/a76/items/series/models.py b/backend/api/v1/modules/a76/items/series/models.py
index 3adda326..0e9bdf45 100644
--- a/backend/api/v1/modules/a76/items/series/models.py
+++ b/backend/api/v1/modules/a76/items/series/models.py
@@ -16,10 +16,13 @@ class Serie(Base, TenantScopedMixin, TimestampMixin):
     serial_numbers: Mapped[Optional[str]] = mapped_column(String(50))  # SERIEEXPO
     model: Mapped[Optional[str]] = mapped_column(String(50))  # MODELOEXPO
     sub_model: Mapped[Optional[str]] = mapped_column(String(50))  # SUBMODELOEXPO
-    brand: Mapped[Optional[str]] = mapped_column(String(50))  # MARCAEXPO    
+    brand: Mapped[Optional[str]] = mapped_column(String(50))  # MARCA
+    # expo_brand: Mapped[Optional[str]] = mapped_column(String(50))  # MARCAEXPO
     number_id: Mapped[Optional[str]] = mapped_column(String(25))  # NUMIDEXPO
     discharge: Mapped[Optional[bool]] = mapped_column(Boolean)  # MARCA
     serie_row: Mapped[Optional[int]] = mapped_column(Integer)  # LINEASERIEIMPO <-- IN CASE OF EXPO
+    # import_invoice: Mapped[Optional[str]] = mapped_column(String(15))  # FACTURAIMPO
+    # import_line: Mapped[Optional[int]] = mapped_column(Integer)  # LINEAIMPO
     image_path: Mapped[Optional[str]] = mapped_column(String(255))  # PATH DE IMAGEN (MEX)
         
     
diff --git a/backend/api/v1/modules/a76/items/series/schemas.py b/backend/api/v1/modules/a76/items/series/schemas.py
index 53d947d7..bb7b42ee 100644
--- a/backend/api/v1/modules/a76/items/series/schemas.py
+++ b/backend/api/v1/modules/a76/items/series/schemas.py
@@ -8,10 +8,10 @@ class SerieBase(BaseModel):
     model: Optional[str] = Field(None, max_length=50, description="Model (MODELOEXPO)")
     sub_model: Optional[str] = Field(None, max_length=50, description="Sub model (SUBMODELOEXPO)")
     brand: Optional[str] = Field(None, max_length=50, description="Brand (MARCA)")
-    expo_brad: Optional[str] = Field(None, max_length=50, description="Expo brand (MARCAEXPO)")
+    # expo_brand: Optional[str] = Field(None, max_length=50, description="Expo brand (MARCAEXPO)")
     number_id: Optional[str] = Field(None, max_length=25, description="Number ID (NUMIDEXPO)")
-    import_invoice: Optional[str] = Field(None, max_length=15, description="Import invoice (FACTURAIMPO)")
-    import_line: Optional[int] = Field(None, description="Import line (LINEAIMPO)")
+    # import_invoice: Optional[str] = Field(None, max_length=15, description="Import invoice (FACTURAIMPO)")
+    # import_line: Optional[int] = Field(None, description="Import line (LINEAIMPO)")
     image_path: Optional[str] = Field(None, max_length=255, description="Image path (IMAGEPATHMEX)")
 
 
diff --git a/backend/api/v1/modules/a76/items/service.py b/backend/api/v1/modules/a76/items/service.py
index 5b6f9477..dd18a443 100644
--- a/backend/api/v1/modules/a76/items/service.py
+++ b/backend/api/v1/modules/a76/items/service.py
@@ -15,7 +15,7 @@ There is no intermediate Item entity anymore. Each LineItem belongs directly to
 import datetime
 import logging
 from decimal import Decimal
-from typing import Optional, List, Tuple
+from typing import Any, Optional, List, Tuple
 from fastapi import HTTPException
 from sqlalchemy import and_, case, func, or_, select
 from sqlalchemy.exc import IntegrityError
@@ -145,6 +145,16 @@ class ItemService:
             )
             return None
 
+    @staticmethod
+    def _filter_model_data(data: dict, model_class: Any) -> dict:
+        """Filter a dictionary to only include keys that exist as attributes in the model class."""
+        if not data:
+            return {}
+        from sqlalchemy import inspect
+        mapper = inspect(model_class)
+        valid_keys = set(mapper.columns.keys())
+        return {k: v for k, v in data.items() if k in valid_keys}
+
     @staticmethod
     def _create_line_nested_data(
         db: Session, line: LineItem, line_data, tenant_id: int, company_id: int
@@ -166,7 +176,9 @@ class ItemService:
                     else data.model_dump()
                 )
                 nested_dict["item_line_id"] = line.id
-                db.add(model_class(**nested_dict))
+                # Filter dict against model attributes
+                filtered_dict = ItemService._filter_model_data(nested_dict, model_class)
+                db.add(model_class(**filtered_dict))
 
         # FA data uses line.id as primary key
         if line_data.fa_data:
@@ -185,7 +197,8 @@ class ItemService:
                 if isinstance(line_data.series, list)
                 else [line_data.series]
             )
-            for s in series_list:
+            new_series = []
+            for i, s in enumerate(series_list):
                 serie_dict = (
                     s.model_dump(exclude_unset=True)
                     if hasattr(s, "model_dump")
@@ -193,12 +206,16 @@ class ItemService:
                 )
                 if not serie_dict:
                     continue
-                serie_dict["line_item_id"] = line.id
-                serie_dict["tenant_id"] = tenant_id
-                serie_dict["company_id"] = company_id
+                serie_dict.update({
+                    "tenant_id": tenant_id,
+                    "company_id": company_id
+                })
                 if serie_dict.get("row") is None:
-                    serie_dict["row"] = 1
-                db.add(Serie(**serie_dict))
+                    serie_dict["row"] = i + 1
+                
+                # Filter dict against model attributes
+                filtered_s = ItemService._filter_model_data(serie_dict, Serie)
+                db.add(Serie(**filtered_s))
 
         # Identifier Detail data
         if hasattr(line_data, "identifiers") and line_data.identifiers:
@@ -207,6 +224,7 @@ class ItemService:
                 if isinstance(line_data.identifiers, list)
                 else [line_data.identifiers]
             )
+            new_ids = []
             for d in id_list:
                 id_dict = (
                     d.model_dump(exclude_unset=True)
@@ -215,10 +233,15 @@ class ItemService:
                 )
                 if not id_dict:
                     continue
-                id_dict["item_line_id"] = line.id
-                id_dict["tenant_id"] = tenant_id
-                id_dict["company_id"] = company_id
-                db.add(IdentifierDetail(**id_dict))
+                id_dict.update({
+                    "tenant_id": tenant_id,
+                    "company_id": company_id
+                })
+                
+                # Filter dict against model attributes
+                filtered_id = ItemService._filter_model_data(id_dict, IdentifierDetail)
+                new_ids.append(IdentifierDetail(**filtered_id))
+            line.identifiers = new_ids
 
     @staticmethod
     def _attach_series(db: Session, item: LineItem) -> None:
@@ -241,6 +264,7 @@ class ItemService:
         )
         item.identifiers = list(identifiers)
 
+
     @staticmethod
     def get_by_id(
         db: Session, item_id: int, tenant_id: int, company_id: int
@@ -257,6 +281,8 @@ class ItemService:
                 joinedload(LineItem.class_info),
                 joinedload(LineItem.unit_of_measure_info),
                 joinedload(LineItem.fa_data),
+                joinedload(LineItem.part_info),
+                joinedload(LineItem.component_part_info),
             )
             .filter(
                 LineItem.id == item_id,
@@ -293,6 +319,8 @@ class ItemService:
                 joinedload(LineItem.class_info),
                 joinedload(LineItem.unit_of_measure_info),
                 joinedload(LineItem.fa_data),
+                joinedload(LineItem.part_info),
+                joinedload(LineItem.component_part_info),
             )
             .filter(
                 LineItem.tenant_id == tenant_id,
@@ -366,6 +394,8 @@ class ItemService:
                 joinedload(LineItem.description),
                 joinedload(LineItem.reference),
                 joinedload(LineItem.fa_data),
+                joinedload(LineItem.part_info),
+                joinedload(LineItem.component_part_info),
             )
             .filter(
                 LineItem.invoice_id == invoice_id,
@@ -505,20 +535,42 @@ class ItemService:
             )
 
             # Create the item
+            # Filter main item_dict against LineItem model attributes
+            item_dict = ItemService._filter_model_data(item_dict, LineItem)
             db_item = LineItem(**item_dict)
             db.add(db_item)
             db.flush()  # Get the item ID
 
-            # Create all nested data
+            # Create nested data
             ItemService._create_line_nested_data(
                 db, db_item, item_data, tenant_id, company_id
             )
 
             db.commit()
-            db.refresh(db_item)
-            ItemService._attach_series(db, db_item)
-            ItemService._attach_identifiers(db, db_item)
-            return db_item
+            
+            # Eager load EVERYTHING needed for the response before returning
+            final_item = (
+                db.query(LineItem)
+                .options(
+                    joinedload(LineItem.financial),
+                    joinedload(LineItem.quantity),
+                    joinedload(LineItem.customs),
+                    joinedload(LineItem.description),
+                    joinedload(LineItem.reference),
+                    joinedload(LineItem.class_info),
+                    joinedload(LineItem.unit_of_measure_info),
+                    joinedload(LineItem.fa_data),
+                    joinedload(LineItem.part_info),
+                    joinedload(LineItem.component_part_info),
+                )
+                .filter(LineItem.id == db_item.id)
+                .first()
+            )
+            
+            if final_item:
+                ItemService._attach_series(db, final_item)
+                ItemService._attach_identifiers(db, final_item)
+            return final_item
 
         except IntegrityError as e:
             db.rollback()
@@ -648,53 +700,111 @@ class ItemService:
                     "reference",
                     "fa_data",
                     "series",
+                    "identifiers",
                 },
                 exclude_unset=True,
             )
 
-            # Update item fields
+            # CONDITIONAL update of nested data to prevent data loss
+            # Perform in-place updates for one-to-one relations, full replacement for one-to-many
+            
+            # Update item attributes
+            # Filter main item_dict against LineItem model attributes
+            item_dict = ItemService._filter_model_data(item_dict, LineItem)
             for key, value in item_dict.items():
                 setattr(db_item, key, value)
 
-            # Delete existing nested data
-            db.query(LineFinancial).filter(
-                LineFinancial.item_line_id == db_item.id
-            ).delete()
-            db.query(LineQuantity).filter(
-                LineQuantity.item_line_id == db_item.id
-            ).delete()
-            db.query(LineCustom).filter(LineCustom.item_line_id == db_item.id).delete()
-            db.query(LineDescription).filter(
-                LineDescription.item_line_id == db_item.id
-            ).delete()
-            db.query(LineReference).filter(
-                LineReference.item_line_id == db_item.id
-            ).delete()
-            db.query(FaLineItem).filter(FaLineItem.id == db_item.id).delete()
-            db.query(Serie).filter(Serie.line_item_id == db_item.id).delete()
-            db.query(IdentifierDetail).filter(IdentifierDetail.item_line_id == db_item.id).delete()
-            db.flush()
+            # 2. Update nested one-to-one objects (In-place update)
+            nested_relations = [
+                ('financial', LineFinancial, 'item_line_id'),
+                ('quantity', LineQuantity, 'item_line_id'),
+                ('customs', LineCustom, 'item_line_id'),
+                ('description', LineDescription, 'item_line_id'),
+                ('reference', LineReference, 'item_line_id')
+            ]
 
-            # Create new nested data
-            ItemService._create_line_nested_data(
-                db, db_item, item_data, tenant_id, company_id
-            )
+            for attr_name, model_class, fk_name in nested_relations:
+                attr_data = getattr(item_data, attr_name)
+                if attr_data is not None:
+                    db_nested = getattr(db_item, attr_name)
+                    nested_dict = attr_data.model_dump(exclude_unset=True)
+                    if db_nested:
+                        # Update existing
+                        for k, v in nested_dict.items():
+                            setattr(db_nested, k, v)
+                    else:
+                        # Create new
+                        nested_dict[fk_name] = db_item.id
+                        new_nested = model_class(**nested_dict)
+                        setattr(db_item, attr_name, new_nested)
+                        db.add(new_nested)
+
+            # 3. Handle fa_data (special case as PK is shared)
+            if item_data.fa_data is not None:
+                fa_dict = item_data.fa_data.model_dump(
+                    exclude_unset=True, exclude={"line_item_id", "includes_subitems"}
+                )
+                if db_item.fa_data:
+                    for k, v in fa_dict.items():
+                        setattr(db_item.fa_data, k, v)
+                else:
+                    fa_dict.update({
+                        "id": db_item.id,
+                        "tenant_id": tenant_id,
+                        "company_id": company_id
+                    })
+                    db_item.fa_data = FaLineItem(**fa_dict)
+                    db.add(db_item.fa_data)
+
+            # 4. Handle one-to-many arrays (Full replacement as these are collections)
+            if item_data.series is not None:
+                # Use synchronize_session='fetch' to ensure the session knows about the deletions
+                db.query(Serie).filter(Serie.line_item_id == db_item.id).delete(synchronize_session='fetch')
+                
+                for s_data in item_data.series:
+                    s_dict = s_data.model_dump(exclude_unset=True)
+                    s_dict.update({
+                        "line_item_id": db_item.id,
+                        "tenant_id": tenant_id,
+                        "company_id": company_id
+                    })
+                    if s_dict.get("row") is None:
+                        s_dict["row"] = 1
+                    
+                    # Filter dict against model attributes
+                    filtered_s = ItemService._filter_model_data(s_dict, Serie)
+                    db.add(Serie(**filtered_s))
+            
+            if item_data.identifiers is not None:
+                db.query(IdentifierDetail).filter(IdentifierDetail.item_line_id == db_item.id).delete()
+                for d in item_data.identifiers:
+                    id_dict = d.model_dump(exclude_unset=True)
+                    id_dict.update({
+                        "item_line_id": db_item.id,
+                        "tenant_id": tenant_id,
+                        "company_id": company_id
+                    })
+                    
+                    # Filter dict against model attributes
+                    filtered_id = ItemService._filter_model_data(id_dict, IdentifierDetail)
+                    db.add(IdentifierDetail(**filtered_id))
+            
+            db.flush()
 
             # Renumber all lines for this invoice to ensure consecutive numbering
             ItemService._renumber_all_invoice_lines(db, db_item.invoice_id)
 
             db.commit()
-            db.refresh(db_item)
-            ItemService._attach_series(db, db_item)
-            ItemService._attach_identifiers(db, db_item)
+            db.refresh(db_item, ["financial", "quantity", "customs", "description", "reference", "fa_data", "identifiers"])
             return db_item
 
         except HTTPException:
             raise
         except Exception as e:
             db.rollback()
+            import traceback
             logger.error(f"Unexpected error updating item: {e}")
-            raise HTTPException(status_code=500, detail="Error updating item")
+            raise HTTPException(status_code=500, detail=f"Error updating item: {str(e)}")
 
     @staticmethod
     def delete(
diff --git a/backend/api/v1/modules/a76/layouts_csv/parts/routes.py b/backend/api/v1/modules/a76/layouts_csv/parts/routes.py
index 2c479dfb..ff833444 100644
--- a/backend/api/v1/modules/a76/layouts_csv/parts/routes.py
+++ b/backend/api/v1/modules/a76/layouts_csv/parts/routes.py
@@ -11,7 +11,7 @@ from fastapi import APIRouter, File, HTTPException, Query, UploadFile, Depends
 from sqlalchemy.orm import Session
 from typing import Dict, Any
 
-from core.celery_app import celery_app
+
 from core.database import get_core_db
 from core.security import get_current_user, validate_access_to_resource
 from api.v1.modules.core.tasks_tracking import track_and_dispatch
@@ -109,6 +109,7 @@ async def upload_import_file(
 
 @router.get("/{job_id}/status")
 async def get_import_status(job_id: str):
+    from core.celery_app import celery_app
     task_result = celery_app.AsyncResult(job_id)
 
     if task_result.state == "PENDING":
diff --git a/backend/api/v1/modules/a76/pedmientos/models/pedimentos.py b/backend/api/v1/modules/a76/pedmientos/models/pedimentos.py
index fe104ac7..4a29b11e 100644
--- a/backend/api/v1/modules/a76/pedmientos/models/pedimentos.py
+++ b/backend/api/v1/modules/a76/pedmientos/models/pedimentos.py
@@ -191,6 +191,7 @@ class Pedimentos(Base, TenantScopedMixin, TimestampMixin):
         uselist=False,
         back_populates="pedimento",
         cascade="all, delete-orphan",
+        lazy="joined",
     )
     pedimento_decrementables: Mapped["PedimentoDecrementables"] = relationship(
         "PedimentoDecrementables",
diff --git a/backend/api/v1/modules/core/tasks_tracking/service.py b/backend/api/v1/modules/core/tasks_tracking/service.py
index 4d98672a..d3485d68 100644
--- a/backend/api/v1/modules/core/tasks_tracking/service.py
+++ b/backend/api/v1/modules/core/tasks_tracking/service.py
@@ -5,7 +5,6 @@ from celery.result import AsyncResult
 from sqlalchemy import asc, desc, func, or_
 from sqlalchemy.orm import Session
 
-from core.celery_app import celery_app
 
 from .models import TaskRun, TaskStatus
 
@@ -142,6 +141,7 @@ class TaskTrackerService:
         return row
 
     def sync_task(self, task_run: TaskRun) -> TaskRun:
+        from core.celery_app import celery_app
         async_result = celery_app.AsyncResult(task_run.task_id)
         raw_state = (async_result.state or "PENDING").upper()
         normalized = normalize_celery_state(raw_state)
diff --git a/backend/core/celery_app.py b/backend/core/celery_app.py
index d7cae18a..d1dae953 100644
--- a/backend/core/celery_app.py
+++ b/backend/core/celery_app.py
@@ -1,24 +1,6 @@
 import os
 from celery import Celery
 
-# Orden: PedimentoCode y RegimenPedimento antes de CodePedimentoRegimen (mapper)
-from api.v1.modules.public.reference_data.pedimento_codes.models import PedimentoCode
-from api.v1.modules.public.reference_data.pedimento_regimens.models import RegimenPedimento
-from api.v1.modules.public.reference_data.code_pedimento_regimens.models import (
-    CodePedimentoRegimen,
-)
-# InvoiceType debe cargarse antes de InvoiceHeader (FK invoice_header.invoice_type -> public.invoice_types.key)
-from api.v1.modules.public.reference_data.invoice_types.models import InvoiceType  # noqa: F401
-# CustomsSection debe cargarse antes de InvoiceComplianceMx (FK invoice_compliance_mx.aduana -> public.customs_sections.customs_code)
-from api.v1.modules.public.reference_data.customs_sections.models import CustomsSection  # noqa: F401
-
-# Import models in correct order for SQLAlchemy relationship resolution
-# CRITICAL: FaLineItem must be imported BEFORE LineItem
-from api.v1.modules.a24.fa.fa_item_lines.models import FaLineItem  # noqa: F401
-from api.v1.modules.a76.items.models import LineItem  # noqa: F401
-# CRITICAL: BalanceMovement must be loaded before DischargeDetail (FK a24.balance_movement)
-from api.v1.modules.a24.balance_movements.models import BalanceMovement  # noqa: F401
-from api.v1.modules.a24.discharges.models import DischargeHeader, DischargeDetail  # noqa: F401
 
 valkey_url = os.getenv("VALKEY_URL", "redis://valkey:6379/0")
 print(f"DEBUG: Celery Broker URL: {valkey_url}")
@@ -31,6 +13,29 @@ celery_app = Celery(
 )
 celery_app.set_default()
 
+# ----------------------------------------------------------------------------
+# Import models in correct order for SQLAlchemy relationship resolution
+# MUST happen AFTER celery_app exists to avoid circular imports during 
+# initialization when models trigger route/task imports.
+# ----------------------------------------------------------------------------
+# Orden: PedimentoCode y RegimenPedimento antes de CodePedimentoRegimen (mapper)
+from api.v1.modules.public.reference_data.pedimento_codes.models import PedimentoCode
+from api.v1.modules.public.reference_data.pedimento_regimens.models import RegimenPedimento
+from api.v1.modules.public.reference_data.code_pedimento_regimens.models import (
+    CodePedimentoRegimen,
+)
+# InvoiceType debe cargarse antes de InvoiceHeader (FK invoice_header.invoice_type -> public.invoice_types.key)
+from api.v1.modules.public.reference_data.invoice_types.models import InvoiceType  # noqa: F401
+# CustomsSection debe cargarse antes de InvoiceComplianceMx (FK invoice_compliance_mx.aduana -> public.customs_sections.customs_code)
+from api.v1.modules.public.reference_data.customs_sections.models import CustomsSection  # noqa: F401
+
+# CRITICAL: FaLineItem must be imported BEFORE LineItem
+from api.v1.modules.a24.fa.fa_item_lines.models import FaLineItem  # noqa: F401
+from api.v1.modules.a76.items.models import LineItem  # noqa: F401
+# CRITICAL: BalanceMovement must be loaded before DischargeDetail (FK a24.balance_movement)
+from api.v1.modules.a24.balance_movements.models import BalanceMovement  # noqa: F401
+from api.v1.modules.a24.discharges.models import DischargeHeader, DischargeDetail  # noqa: F401
+
 celery_app.conf.update(
     include=[
         "api.v1.modules.a76.reports.importacion.facturas.task",
diff --git a/frontend/src/lib/components/dashboard/invoices/edit/items/fa/item-configuration.svelte b/frontend/src/lib/components/dashboard/invoices/edit/items/fa/item-configuration.svelte
index 3ba8056a..f6505bab 100644
--- a/frontend/src/lib/components/dashboard/invoices/edit/items/fa/item-configuration.svelte
+++ b/frontend/src/lib/components/dashboard/invoices/edit/items/fa/item-configuration.svelte
@@ -43,11 +43,19 @@
 	}
 
 	function handlePartSelect(part: any) {
-		lineItem.part_number = part.id;
+		lineItem.part_number_id = part.id;
+		lineItem.part_number = part.part_number;
 		// Store part number for display
 		(lineItem as any).part_number_display = part.part_number;
 		(lineItem as any).part_description_es = part.description_spanish;
 		(lineItem as any).part_description_en = part.description_english;
+
+		// Update actual values if descriptions container exists
+		if (descriptions) {
+			if (part.description_spanish) descriptions.description_spanish = part.description_spanish;
+			if (part.description_english) descriptions.description_english = part.description_english;
+		}
+
 		if (!lineItem.fda_key && part.fda_key) {
 			lineItem.fda_key = part.fda_key;
 		}
diff --git a/frontend/src/lib/components/dashboard/invoices/edit/items/fa/tab-series.svelte b/frontend/src/lib/components/dashboard/invoices/edit/items/fa/tab-series.svelte
index 08671076..9e93e649 100644
--- a/frontend/src/lib/components/dashboard/invoices/edit/items/fa/tab-series.svelte
+++ b/frontend/src/lib/components/dashboard/invoices/edit/items/fa/tab-series.svelte
@@ -4,7 +4,7 @@
 	import { Checkbox } from '$lib/components/ui/checkbox';
 	import { Label } from '$lib/components/ui/label';
 	import { Button } from '$lib/components/ui/button';
-	import { Plus, Pencil } from 'lucide-svelte';
+	import { Plus, Pencil, Trash2, CheckCircle2 } from 'lucide-svelte';
 	import type { Item, LineDescriptions, Serie } from '$lib/api/dashboard/a76/items';
 	import type { Invoice } from '$lib/api/dashboard/a76/invoices';
 
@@ -57,6 +57,19 @@
 		selectedSeriesIndex = null;
 	}
 
+	function deleteSerie(index: number) {
+		const arr = ensureSeriesArray();
+		const newArr = arr.filter((_, i) => i !== index);
+		// Update row numbers for remaining series
+		newArr.forEach((s, i) => (s.row = i + 1));
+		series = newArr;
+		if (selectedSeriesIndex === index) {
+			selectedSeriesIndex = null;
+		} else if (selectedSeriesIndex !== null && selectedSeriesIndex > index) {
+			selectedSeriesIndex--;
+		}
+	}
+
 	// Current serie being edited (reference into the array)
 	const currentSerie = $derived(
 		selectedSeriesIndex !== null && seriesList[selectedSeriesIndex] != null
@@ -65,12 +78,7 @@
 	);
 
 	const internalHasSerial = $derived(descriptions?.has_serial === true);
-	function toggleHasSerial() {
-		if (descriptions) {
-			descriptions.has_serial = !descriptions.has_serial;
-		}
-	}
-
+	
 	const hasSerial = $derived(internalHasSerial);
 
 	// Ensure current serie has defaults for form fields
@@ -159,16 +167,16 @@
 	</div>
 
 	<!-- Table of all series for this item -->
-	<div class="rounded-md border overflow-hidden">
+	<div class="rounded-md border overflow-hidden max-h-[300px] overflow-y-auto">
 		<Table.Root>
-			<Table.Header>
+			<Table.Header class="sticky top-0 bg-white dark:bg-zinc-950 z-10">
 				<Table.Row class="bg-muted/50">
-					<Table.Head class="w-12 text-center text-xs">Línea</Table.Head>
-					<Table.Head class="text-xs">Serie</Table.Head>
-					<Table.Head class="text-xs">Modelo</Table.Head>
-					<Table.Head class="text-xs">Sub modelo</Table.Head>
-					<Table.Head class="text-xs">Núm. ID</Table.Head>
-					<Table.Head class="w-[80px] text-right text-xs">Acciones</Table.Head>
+					<Table.Head class="w-12 text-center text-[10px] uppercase">Línea</Table.Head>
+					<Table.Head class="text-[10px] uppercase text-center">Serie</Table.Head>
+					<Table.Head class="text-[10px] uppercase text-center">Modelo</Table.Head>
+					<Table.Head class="text-[10px] uppercase text-center">Sub modelo</Table.Head>
+					<Table.Head class="text-[10px] uppercase text-center">Núm. ID</Table.Head>
+					<Table.Head class="w-[80px] text-right text-[10px] uppercase">Acciones</Table.Head>
 				</Table.Row>
 			</Table.Header>
 			<Table.Body>
@@ -187,22 +195,22 @@
 							onclick={() => hasSerial && selectForEdit(i)}
 						>
 							<Table.Cell class="text-center text-xs font-medium">{serie.row ?? i + 1}</Table.Cell>
-							<Table.Cell class="text-xs max-w-[120px] truncate" title={serie.serial_numbers}>
+							<Table.Cell class="text-xs max-w-[120px] truncate text-center" title={serie.serial_numbers}>
 								{serie.serial_numbers || '-'}
 							</Table.Cell>
-							<Table.Cell class="text-xs max-w-[100px] truncate" title={serie.model}>
+							<Table.Cell class="text-xs max-w-[100px] truncate text-center" title={serie.model}>
 								{serie.model || '-'}
 							</Table.Cell>
-							<Table.Cell class="text-xs max-w-[100px] truncate" title={serie.sub_model}>
+							<Table.Cell class="text-xs max-w-[100px] truncate text-center" title={serie.sub_model}>
 								{serie.sub_model || '-'}
 							</Table.Cell>
-							<Table.Cell class="text-xs">{serie.number_id || '-'}</Table.Cell>
-							<Table.Cell class="text-right">
+							<Table.Cell class="text-xs text-center">{serie.number_id || '-'}</Table.Cell>
+							<Table.Cell class="text-right flex items-center justify-end gap-1">
 								<Button
 									type="button"
 									variant="ghost"
 									size="icon"
-									class="h-7 w-7"
+									class="h-7 w-7 text-blue-600"
 									disabled={!hasSerial}
 									onclick={(e) => {
 										e.stopPropagation();
@@ -211,6 +219,19 @@
 								>
 									<Pencil class="w-3.5 h-3.5" />
 								</Button>
+								<Button
+									type="button"
+									variant="ghost"
+									size="icon"
+									class="h-7 w-7 text-red-600 hover:text-red-700 hover:bg-red-50"
+									disabled={!hasSerial}
+									onclick={(e) => {
+										e.stopPropagation();
+										if (hasSerial) deleteSerie(i);
+									}}
+								>
+									<Trash2 class="w-3.5 h-3.5" />
+								</Button>
 							</Table.Cell>
 						</Table.Row>
 					{/each}
@@ -221,42 +242,57 @@
 
 	<!-- Form for selected or new serie -->
 	{#if currentSerie && selectedSeriesIndex !== null}
-		<div class="mt-3 pt-3 border-t space-y-3">
+		<div class="mt-3 pt-3 border-t-2 border-primary/20 space-y-3 bg-primary/5 p-3 rounded-lg animate-in fade-in slide-in-from-top-2 duration-300">
 			<div class="flex items-center justify-between">
-				<span class="text-xs font-medium text-muted-foreground">
-					{selectedSeriesIndex >= seriesList.length - 1 && !currentSerie?.id
-						? 'Nueva serie'
-						: `Editar serie (línea ${currentSerie.row ?? selectedSeriesIndex + 1})`}
-				</span>
-				<Button type="button" variant="ghost" size="sm" class="h-6 text-xs" onclick={clearSelection}>
-					Cerrar formulario
-				</Button>
+				<div class="flex items-center gap-2">
+					<div class="w-2 h-2 bg-primary rounded-full"></div>
+					<span class="text-xs font-bold uppercase tracking-wider text-primary">
+						{selectedSeriesIndex >= (seriesList.length - 1) && !currentSerie?.id
+							? 'Capturando Nueva serie'
+							: `Editando serie (línea ${currentSerie.row ?? selectedSeriesIndex + 1})`}
+					</span>
+				</div>
+				<div class="flex gap-2">
+					<Button 
+						type="button" 
+						variant="default" 
+						size="sm" 
+						class="h-7 text-xs bg-emerald-600 hover:bg-emerald-700 text-white gap-1" 
+						onclick={clearSelection}
+					>
+						<CheckCircle2 class="w-3.5 h-3.5" />
+						Aceptar / Listo
+					</Button>
+					<Button type="button" variant="outline" size="sm" class="h-7 text-xs" onclick={clearSelection}>
+						Cerrar
+					</Button>
+				</div>
 			</div>
 			<div class="grid grid-cols-1 md:grid-cols-2 gap-3">
 				<div class="space-y-2">
-					<Label for="invoice_number" class="text-xs">NUMERO FACTURA:</Label>
+					<Label for="invoice_number" class="text-xs font-semibold">NUMERO FACTURA:</Label>
 					<div
 						id="invoice_number"
-						class="flex h-8 w-full items-center rounded-md border border-input bg-muted/40 px-3 text-sm text-foreground"
+						class="flex h-8 w-full items-center rounded-md border border-input bg-muted/60 px-3 text-sm text-foreground font-mono"
 					>
 						{invoiceNumber || '-'}
 					</div>
 				</div>
 				<div class="space-y-2">
-					<Label for="invoice_line" class="text-xs">LINEA FACTURA:</Label>
+					<Label for="invoice_line" class="text-xs font-semibold">LINEA FACTURA:</Label>
 					<div
 						id="invoice_line"
-						class="flex h-8 w-full items-center rounded-md border border-input bg-muted/40 px-3 text-sm text-foreground"
+						class="flex h-8 w-full items-center rounded-md border border-input bg-muted/60 px-3 text-sm text-foreground font-mono"
 					>
 						{invoiceLine || '-'}
 					</div>
 				</div>
 				<div class="space-y-2">
-					<Label for="series_row" class="text-xs">LINEA SERIE:</Label>
+					<Label for="series_row" class="text-xs font-semibold">LINEA SERIE:</Label>
 					<Input
 						id="series_row"
 						bind:value={currentSerie.row}
-						class="h-8 text-sm"
+						class="h-8 text-sm focus:ring-primary"
 						type="number"
 						min={1}
 						step={1}
@@ -265,11 +301,11 @@
 					/>
 				</div>
 				<div class="space-y-2">
-					<Label for="serial_number" class="text-xs">SERIE:</Label>
+					<Label for="serial_number" class="text-xs font-semibold">SERIE:</Label>
 					<Input
 						id="serial_number"
 						value={currentSerie.serial_numbers ?? ''}
-						class="h-8 text-sm"
+						class="h-8 text-sm focus:ring-primary"
 						maxlength={50}
 						placeholder="Número de serie..."
 						disabled={!hasSerial}
@@ -277,11 +313,11 @@
 					/>
 				</div>
 				<div class="space-y-2">
-					<Label for="series_model" class="text-xs">MODELO:</Label>
+					<Label for="series_model" class="text-xs font-semibold">MODELO:</Label>
 					<Input
 						id="series_model"
 						value={currentSerie.model ?? ''}
-						class="h-8 text-sm"
+						class="h-8 text-sm focus:ring-primary"
 						maxlength={50}
 						placeholder="Modelo..."
 						disabled={!hasSerial}
@@ -289,20 +325,20 @@
 					/>
 				</div>
 				<div class="space-y-2">
-					<Label for="part_number" class="text-xs">NUM PARTE:</Label>
+					<Label for="part_number" class="text-xs font-semibold">NUM PARTE:</Label>
 					<div
 						id="part_number"
-						class="flex h-8 w-full items-center rounded-md border border-input bg-muted/40 px-3 text-sm text-foreground"
+						class="flex h-8 w-full items-center rounded-md border border-input bg-muted/60 px-3 text-sm text-foreground font-mono"
 					>
 						{partNumber || '-'}
 					</div>
 				</div>
 				<div class="space-y-2">
-					<Label for="sub_model" class="text-xs">SUB MODELO:</Label>
+					<Label for="sub_model" class="text-xs font-semibold">SUB MODELO:</Label>
 					<Input
 						id="sub_model"
 						value={currentSerie.sub_model ?? ''}
-						class="h-8 text-sm"
+						class="h-8 text-sm focus:ring-primary"
 						maxlength={50}
 						placeholder="Sub modelo..."
 						disabled={!hasSerial}
@@ -310,11 +346,11 @@
 					/>
 				</div>
 				<div class="space-y-2">
-					<Label for="number_id" class="text-xs">NUMERO ID:</Label>
+					<Label for="number_id" class="text-xs font-semibold">NUMERO ID:</Label>
 					<Input
 						id="number_id"
 						value={currentSerie.number_id ?? ''}
-						class="h-8 text-sm"
+						class="h-8 text-sm focus:ring-primary"
 						maxlength={25}
 						placeholder="Número ID..."
 						disabled={!hasSerial}
@@ -322,12 +358,43 @@
 					/>
 				</div>
 			</div>
+			<div class="flex justify-end pt-1">
+				<Button 
+					type="button" 
+					variant="ghost" 
+					size="sm" 
+					class="h-7 text-xs text-red-600 hover:text-red-700 hover:bg-red-50 gap-1" 
+					onclick={() => deleteSerie(selectedSeriesIndex!)}
+				>
+					<Trash2 class="w-3.5 h-3.5" />
+					Eliminar esta serie
+				</Button>
+			</div>
 		</div>
 	{/if}
 
-	<div class="text-xs text-muted-foreground">
+	<div class="text-xs text-muted-foreground italic bg-zinc-50 dark:bg-zinc-900 p-2 rounded border-l-4 border-zinc-300">
 		{#if !hasSerial}
 			Los datos capturados se conservan, pero la edición queda deshabilitada mientras "Lleva serie" esté apagado.
+		{:else}
+			Se permiten hasta {maxSeriesAllowed === Infinity ? 'ilimitadas' : maxSeriesAllowed} series para esta partida.
 		{/if}
 	</div>
 </fieldset>
+
+<style>
+	/* Animación para el formulario de edición */
+	.animate-in {
+		animation: fadeInSlide 0.3s ease-out;
+	}
+	@keyframes fadeInSlide {
+		from {
+			opacity: 0;
+			transform: translateY(-8px);
+		}
+		to {
+			opacity: 1;
+			transform: translateY(0);
+		}
+	}
+</style>
diff --git a/frontend/src/lib/components/dashboard/invoices/edit/items/inv/item-sheet-inv.svelte b/frontend/src/lib/components/dashboard/invoices/edit/items/inv/item-sheet-inv.svelte
index 99d52d99..4aeeaca1 100644
--- a/frontend/src/lib/components/dashboard/invoices/edit/items/inv/item-sheet-inv.svelte
+++ b/frontend/src/lib/components/dashboard/invoices/edit/items/inv/item-sheet-inv.svelte
@@ -54,12 +54,13 @@
 	};
 
 	function handlePartSelect(part: any) {
-		editingItem.part_number = part.id;
+		editingItem.part_number_id = part.id;
+		editingItem.part_number = part.part_number;
 		// Store part number for display
 		(editingItem as any).part_number_display = part.part_number;
 		if (editingItem.description) {
-			editingItem.description.description_spanish = part.description_spanish;
-			editingItem.description.description_english = part.description_english;
+			if (part.description_spanish) editingItem.description.description_spanish = part.description_spanish;
+			if (part.description_english) editingItem.description.description_english = part.description_english;
 		}
 		if (editingItem.customs) {
 			editingItem.customs.fraction = part.fraction;
@@ -93,8 +94,10 @@
 
 	function handleCountrySelect(country: any) {
 		if (!editingItem.customs) editingItem.customs = {} as any;
-		editingItem.customs.origin_country = country.m3_key || country.mex_key;
-		(editingItem.customs as any).origin_country_name = country.description || country.description_en;
+		if (editingItem.customs) {
+			editingItem.customs.origin_country = country.m3_key || country.mex_key;
+			(editingItem.customs as any).origin_country_name = country.description || country.description_en;
+		}
 	}
 
 	function handleFractionSelect(fraction: any) {
@@ -360,16 +363,28 @@
 						</div>
 					</div>
 
-					<!-- Campos específicos de SCAII -->
-					<div class="space-y-2">
-						<Label for="product_description">Descripción del Producto</Label>
-						{#if editingItem?.description}
-							<Input
-								id="product_description"
-								placeholder="Descripción detallada del producto"
-								bind:value={editingItem.description.description_spanish}
-							/>
-						{/if}
+					<!-- Campos específicos de SCAII: Descripciones -->
+					<div class="grid grid-cols-1 md:grid-cols-2 gap-4">
+						<div class="space-y-2">
+							<Label for="product_description_es">Descripción (Español) <span class="text-red-500">*</span></Label>
+							{#if editingItem?.description}
+								<Input
+									id="product_description_es"
+									placeholder="Descripción en español"
+									bind:value={editingItem.description.description_spanish}
+								/>
+							{/if}
+						</div>
+						<div class="space-y-2">
+							<Label for="product_description_en">Descripción (Inglés)</Label>
+							{#if editingItem?.description}
+								<Input
+									id="product_description_en"
+									placeholder="Description in English"
+									bind:value={editingItem.description.description_english}
+								/>
+							{/if}
+						</div>
 					</div>
 
 					<div class="grid grid-cols-2 gap-4">
diff --git a/frontend/src/lib/components/dashboard/invoices/edit/items/items-tab-form.svelte b/frontend/src/lib/components/dashboard/invoices/edit/items/items-tab-form.svelte
index 9cd4aa80..dd6eb2b2 100644
--- a/frontend/src/lib/components/dashboard/invoices/edit/items/items-tab-form.svelte
+++ b/frontend/src/lib/components/dashboard/invoices/edit/items/items-tab-form.svelte
@@ -26,7 +26,7 @@
 	import ItemSheetInv from './inv/item-sheet-inv.svelte';
 	import { itemPresetsApi, type ItemPreset } from '$lib/api/dashboard/a76/item-presets';
 	import { Checkbox } from '$lib/components/ui/checkbox';
-	import { cleanLineData } from '$lib/utils/items-logic';
+	import { cleanLineData, normalizeItemData } from '$lib/utils/items-logic';
 	import { getVisibility } from '$lib/config/invoice-item-visibility';
 
 	let {
@@ -263,40 +263,6 @@
 		}
 	}
 
-	function normalizeItemData(item: Partial<InvoiceItem>): Partial<InvoiceItem> {
-		if (!item) return {};
-		const normalizedItem = { ...item };
-
-		if (normalizedItem.financial) {
-			normalizedItem.financial = {
-				...normalizedItem.financial,
-				unit_cost_usd: normalizedItem.financial.unit_cost_usd != null ? Number(normalizedItem.financial.unit_cost_usd) : undefined,
-				unit_cost_mxn: normalizedItem.financial.unit_cost_mxn != null ? Number(normalizedItem.financial.unit_cost_mxn) : undefined,
-				value_usd: normalizedItem.financial.value_usd != null ? Number(normalizedItem.financial.value_usd) : undefined,
-				value_mxn: normalizedItem.financial.value_mxn != null ? Number(normalizedItem.financial.value_mxn) : undefined
-			};
-		} else {
-			normalizedItem.financial = { unit_cost_usd: undefined };
-		}
-
-		if (normalizedItem.quantity) {
-			normalizedItem.quantity = {
-				...normalizedItem.quantity,
-				quantity: normalizedItem.quantity.quantity != null ? Number(normalizedItem.quantity.quantity) : undefined,
-				net_weight: normalizedItem.quantity.net_weight != null ? Number(normalizedItem.quantity.net_weight) : undefined,
-				gross_weight: normalizedItem.quantity.gross_weight != null ? Number(normalizedItem.quantity.gross_weight) : undefined,
-				package_quantity: normalizedItem.quantity.package_quantity != null ? Number(normalizedItem.quantity.package_quantity) : undefined
-			};
-		} else {
-			normalizedItem.quantity = { quantity: undefined };
-		}
-		
-		if (!normalizedItem.customs) normalizedItem.customs = { origin_country: undefined, fraction_type: undefined };
-		if (!normalizedItem.description) normalizedItem.description = { description_spanish: undefined };
-		if (!normalizedItem.fa_data) normalizedItem.fa_data = {};
-
-		return normalizedItem;
-	}
 
 	function handleAdd() {
 		if (!showCreatePresetDialog && !invoice?.id) {
diff --git a/frontend/src/lib/components/dashboard/invoices/settings/sscr-settings-form.svelte b/frontend/src/lib/components/dashboard/invoices/settings/sscr-settings-form.svelte
index a2272735..7d8cfc1b 100644
--- a/frontend/src/lib/components/dashboard/invoices/settings/sscr-settings-form.svelte
+++ b/frontend/src/lib/components/dashboard/invoices/settings/sscr-settings-form.svelte
@@ -120,7 +120,7 @@
 		PackingPedClave: false,
 
 		// SCAF specific
-		AsignaValoresTC: 'exportacion',
+		ValFactTC: 'TCE',
 		pagoimpuesto: 'no',
 		formapago: '',
 		SolicitarPswdDesactualizar: false,
@@ -206,16 +206,16 @@
 									Asigna Valores a partidas en Base al T.C de:
 								</Label>
 								<RadioGroup
-									value={formData.AsignaValoresTC}
-									onValueChange={(v) => (formData.AsignaValoresTC = v)}
+									value={formData.ValFactTC}
+									onValueChange={(v) => (formData.ValFactTC = v)}
 									class="flex gap-6 justify-center mt-2"
 								>
 									<div class="flex items-center gap-2">
-										<RadioGroupItem value="importacion" id="cr_tc_imp" />
+										<RadioGroupItem value="PER_LINE" id="cr_tc_imp" />
 										<Label for="cr_tc_imp" class="text-sm">Importación</Label>
 									</div>
 									<div class="flex items-center gap-2">
-										<RadioGroupItem value="exportacion" id="cr_tc_exp" />
+										<RadioGroupItem value="TCE" id="cr_tc_exp" />
 										<Label for="cr_tc_exp" class="text-sm">Exportación</Label>
 									</div>
 								</RadioGroup>
diff --git a/frontend/src/lib/components/ui/dialog/index.ts b/frontend/src/lib/components/ui/dialog/index.ts
index dce1d9dc..80edaf2a 100644
--- a/frontend/src/lib/components/ui/dialog/index.ts
+++ b/frontend/src/lib/components/ui/dialog/index.ts
@@ -9,8 +9,8 @@ import Description from "./dialog-description.svelte";
 import Trigger from "./dialog-trigger.svelte";
 import Close from "./dialog-close.svelte";
 
-const Root = DialogPrimitive.Root;
-const Portal = DialogPrimitive.Portal;
+const Root = DialogPrimitive?.Root ?? (class {} as any);
+const Portal = DialogPrimitive?.Portal ?? (class {} as any);
 
 export {
 	Root,
diff --git a/frontend/src/lib/utils/items-logic.ts b/frontend/src/lib/utils/items-logic.ts
index de44d0e4..2b78ffc2 100644
--- a/frontend/src/lib/utils/items-logic.ts
+++ b/frontend/src/lib/utils/items-logic.ts
@@ -1,170 +1,246 @@
-
-export interface Item {
-    id?: number;
-    [key: string]: any;
-}
-
-// Helper function to check if an object has any meaningful values
-export function hasValues(obj: any): boolean {
-    if (!obj || typeof obj !== 'object') return false;
-    
-    // Si el objeto está intencionalmente vacío o tiene campos que serán usados,
-    // es mejor dejar que el backend valide si es requerido.
-    const values = Object.values(obj);
-    if (values.length === 0) return false;
-    
-    return values.some(
-        (val) =>
-            val !== undefined &&
-            val !== null &&
-            val !== '' &&
-            !(typeof val === 'object' && !hasValues(val))
-    );
-}
-
-// Clean nested data before sending to API
-export function cleanLineData(line: any) {
-    // 1. First, deeply copy and unwrap any Svelte Proxies to ensure a clean JS object
-    const rawLine = JSON.parse(JSON.stringify(line));
-    const cleaned: any = { ...rawLine };
-
-    // Helper function to convert to number or undefined
-    const toNumberOrUndefined = (value: any): number | undefined => {
-        if (value === undefined || value === null || value === '') {
-            return undefined;
-        }
-        const numValue = Number(value);
-        return !isNaN(numValue) && isFinite(numValue) ? numValue : undefined;
-    };
-
-    // Explicitly keep mandatory fields for a76 schema
-    cleaned.invoice_id = toNumberOrUndefined(rawLine.invoice_id);
-    cleaned.line_number = toNumberOrUndefined(rawLine.line_number);
-    
-    // Reconstruction approach for core objects to be 100% sure
-    // We ALWAYS want these objects to exist in the payload even if all fields are null
-    // so the backend validation layer doesn't crash (AttributeError on None)
-    
-    cleaned.financial = {
-        unit_cost_usd: rawLine.financial ? toNumberOrUndefined(rawLine.financial.unit_cost_usd) : undefined,
-        unit_cost_mxn: rawLine.financial ? toNumberOrUndefined(rawLine.financial.unit_cost_mxn) : undefined,
-        unit_cost_capture: rawLine.financial ? toNumberOrUndefined(rawLine.financial.unit_cost_capture) : undefined,
-        value_mc: rawLine.financial ? toNumberOrUndefined(rawLine.financial.value_mc) : undefined,
-        value_usd: rawLine.financial ? toNumberOrUndefined(rawLine.financial.value_usd) : undefined,
-        value_mxn: rawLine.financial ? toNumberOrUndefined(rawLine.financial.value_mxn) : undefined
-    };
-
-    cleaned.quantity = {
-        quantity: rawLine.quantity ? (toNumberOrUndefined(rawLine.quantity.quantity) || 0) : 0,
-        net_weight: rawLine.quantity ? toNumberOrUndefined(rawLine.quantity.net_weight) : undefined,
-        gross_weight: rawLine.quantity ? toNumberOrUndefined(rawLine.quantity.gross_weight) : undefined,
-        package_id: rawLine.quantity ? toNumberOrUndefined(rawLine.quantity.package_id) : undefined,
-        package_quantity: rawLine.quantity ? toNumberOrUndefined(rawLine.quantity.package_quantity) : undefined
-        // NOTE: unit_of_measure lives at the top-level LineItem, NOT inside quantity
-    };
-
-    cleaned.description = {
-        description_spanish: rawLine.description ? (rawLine.description.description_spanish || '') : '',
-        description_english: rawLine.description ? (rawLine.description.description_english || '') : '',
-        brand: rawLine.description ? (rawLine.description.brand || '') : '',
-        model: rawLine.description ? (rawLine.description.model || '') : ''
-    };
-    
-    cleaned.customs = {
-        fraction: rawLine.customs ? (rawLine.customs.fraction || undefined) : undefined,
-        american_fraction: rawLine.customs ? (rawLine.customs.american_fraction || undefined) : undefined,
-        origin_country: rawLine.customs ? (rawLine.customs.origin_country || undefined) : undefined,
-        fraction_type: rawLine.customs ? (rawLine.customs.fraction_type || undefined) : undefined
-    };
-
-    // Convert integer fields (only if they look like numbers/IDs)
-    if (cleaned.part_number && !isNaN(Number(cleaned.part_number))) {
-        cleaned.part_number = toNumberOrUndefined(cleaned.part_number);
-    }
-    
-    cleaned.component_part_number = toNumberOrUndefined(cleaned.component_part_number);
-    cleaned.class_id = toNumberOrUndefined(cleaned.class_id);
-    
-    // Ensure part_number is preserved if it's a string (common in some modules)
-    if (rawLine.part_number && !cleaned.part_number) {
-        cleaned.part_number = rawLine.part_number;
-    }
-
-    cleaned.unit_of_measure = toNumberOrUndefined(cleaned.unit_of_measure);
-    cleaned.alternate_unit = toNumberOrUndefined(cleaned.alternate_unit);
-
-    // Remove ALL display-only and UI-specific fields that the backend schema doesn't know about
-    delete cleaned.class_code;
-    delete cleaned.class_unit_of_measure;
-    delete cleaned.class_description;
-    delete cleaned.part_description_es;
-    delete cleaned.part_description_en;
-    delete cleaned.part_number_display;   // UI display field for part number string
-    delete cleaned.unit_code;
-    delete cleaned.unit_description;
-    delete cleaned.includes_subitems;
-    delete cleaned.payment_method_description;
-    // Remove any other unknown top-level display fields
-    delete (cleaned as any).class_unit_of_measure_description;
-
-    // Remove display-only fields from nested objects
-    if (cleaned.customs) {
-        delete cleaned.customs.origin_country_name;
-        delete cleaned.customs.fraction_description;
-        // DO NOT delete if empty - backend needs the object structure
-    }
-
-    if (cleaned.fa_data) {
-        delete cleaned.fa_data.includes_subitems;
-        // Keep fa_data as is otherwise (unwrapped by stringify/parse above)
-    }
-
-    if (cleaned.series != null) {
-        const arr = Array.isArray(cleaned.series) ? cleaned.series : [cleaned.series];
-        cleaned.series = arr
-            .map((s: any) => {
-                if (!s || typeof s !== 'object') return null;
-                const { id, line_item_id, ...rest } = s;
-                return hasValues(rest) ? rest : null;
-            })
-            .filter((s: any) => s != null);
-        if (cleaned.series.length === 0) delete cleaned.series;
-    }
-
-    return cleaned;
-}
-
-// Normalize numeric values from strings to numbers (for editing)
-export function normalizeItemData(item: Partial<Item>): Partial<Item> {
-    if (item) {
-        const normalizedItem = { ...item };
-
-        // Normalize financials
-        if (normalizedItem.financial) {
-            const f = normalizedItem.financial;
-            normalizedItem.financial = {
-                ...f,
-                unit_cost_usd: f.unit_cost_usd != null ? Number(f.unit_cost_usd) : undefined,
-                unit_cost_mxn: f.unit_cost_mxn != null ? Number(f.unit_cost_mxn) : undefined,
-                value_usd: f.value_usd != null ? Number(f.value_usd) : undefined,
-                value_mxn: f.value_mxn != null ? Number(f.value_mxn) : undefined
-            };
-        }
-
-        // Normalize quantities
-        if (normalizedItem.quantity) {
-            const q = normalizedItem.quantity;
-            normalizedItem.quantity = {
-                ...q,
-                quantity: q.quantity != null ? Number(q.quantity) : undefined,
-                net_weight: q.net_weight != null ? Number(q.net_weight) : undefined,
-                gross_weight: q.gross_weight != null ? Number(q.gross_weight) : undefined,
-                package_quantity: q.package_quantity != null ? Number(q.package_quantity) : undefined
-            };
-        }
-
-        return normalizedItem;
-    }
-
-    return item;
-}
+
+// Helper function to convert to number or undefined
+const toNumberOrUndefined = (value: any): number | undefined => {
+    if (value === undefined || value === null || value === '') {
+        return undefined;
+    }
+    const numValue = Number(value);
+    return !isNaN(numValue) && isFinite(numValue) ? numValue : undefined;
+};
+
+// Fields that should be converted to numbers if they exist
+const NUMERIC_FIELDS = [
+    // Top-level
+    'invoice_id', 'line_number', 'part_number_id', 'component_part_number_id', 'class_id',
+    'unit_of_measure', 'alternate_unit', 'consecutive_destination', 'consecutive_aphis',
+    'bom_version', 'bill_version', 'tlcan_value', 'validation_zero', 'validation_one',
+    'take_component_pt', 'pallet2', 'rectification',
+
+    // Financial
+    'unit_cost_capture', 'unit_cost_usd', 'unit_cost_commercial_usd', 'unit_cost_current_usd',
+    'unit_cost_depreciated_usd', 'unit_cost_subitem_usd', 'unit_cost_auxiliary_usd',
+    'sales_cost_usd', 'commercial_unit_cost', 'unit_cost_mxn', 'unit_cost_commercial_mxn',
+    'unit_cost_current_mxn', 'unit_cost_depreciated_mxn', 'unit_cost_subitem_mxn',
+    'sales_cost_mxn', 'unit_cost_mc', 'value_mxn', 'value_commercial_mxn', 'value_updated_mxn',
+    'value_subitem_mxn', 'sub_import_value_mxn', 'value_returned_mxn', 'value_depreciated_mxn',
+    'customs_value_mxn', 'value_total_mxn', 'value_temp_material_mxn', 'value_def_material_mxn',
+    'value_added_mxn', 'value_national_packing_mxn', 'vat_mxn', 'vat_used_mxn',
+    'advalorem_line_mxn', 'value_usd', 'value_commercial_usd', 'value_updated_usd',
+    'value_subitem_usd', 'sub_import_value_usd', 'value_returned_usd', 'value_depreciated_usd',
+    'customs_value_usd', 'value_auxiliary_usd', 'value_total_usd', 'value_temp_material_usd',
+    'value_def_material_usd', 'value_added_usd', 'value_national_packing_usd',
+    'value_us_packing_usd', 'vat_usd', 'vat_used_usd', 'value_non_originating_usd',
+    'value_originating_usd', 'igi_amount_usd', 'exempt_amount_usd', 'total_commercial_value',
+    'advalorem_line_usd', 'value_mc', 'sub_import_value_mc', 'vat_mc', 'value_added_mc',
+    'value_national_packing_mc', 'value_total_mc', 'value_temp_material_mc', 'value_def_material_mc',
+
+    // Quantity
+    'quantity', 'alternate_quantity', 'quantity_uma', 'auxiliary_quantity',
+    'quantity_temp_export', 'serial_count', 'net_weight', 'gross_weight',
+    'package_id', 'package_quantity', 'container_quantity',
+
+    // Customs
+    'advalorem_numeric', 'advalorem_american', 'advalorem_tlcan', 'depreciation_rate',
+
+    // Description
+    'eighth_rule_line',
+
+    // Series
+    'row', 'serie_row', 'import_line',
+
+    // Identifiers
+    'invoice_consecutive', 'part_line',
+
+    // FA Data
+    'return_import_date', 'subitem_number', 'search_line'
+];
+
+// UI/Display only fields that should be removed before sending to API
+const UI_BLACKLIST = [
+    'class_code', 'class_unit_of_measure', 'class_description', 'part_description_es',
+    'part_description_en', 'part_number_display', 'unit_code', 'unit_description',
+    'includes_subitems', 'payment_method_description', 'class_unit_of_measure_description',
+    'origin_country_name', 'fraction_description', 'id' // Remove ID for creates, but update handles it via URL
+];
+
+// Clean nested data before sending to API
+export function cleanLineData(line: any) {
+    // 1. Deep clone to unwrap proxies and avoid mutations
+    const cleaned = JSON.parse(JSON.stringify(line));
+
+    // 2. Helper to clean an object recursively
+    const processObject = (obj: any) => {
+        if (!obj || typeof obj !== 'object' || Array.isArray(obj)) return;
+
+        Object.keys(obj).forEach(key => {
+            // Remove blacklisted fields
+            if (UI_BLACKLIST.includes(key)) {
+                delete obj[key];
+                return;
+            }
+
+            // Convert numeric fields - ONLY if it's not one of our known containers
+            const containers = ['financial', 'quantity', 'customs', 'description', 'fa_data', 'reference'];
+            const isContainer = containers.includes(key);
+
+            if (NUMERIC_FIELDS.includes(key) && !isContainer) {
+                obj[key] = toNumberOrUndefined(obj[key]);
+            }
+
+            // Recurse into nested objects if it's one of our known containers
+            if (isContainer && obj[key]) {
+                processObject(obj[key]);
+            }
+        });
+    };
+
+    // 3. Process the top level and nested objects
+    processObject(cleaned);
+
+    // 4. Special handling for Series and Identifiers (arrays)
+    if (cleaned.series && Array.isArray(cleaned.series)) {
+        cleaned.series = cleaned.series.map((s: any) => {
+            if (typeof s !== 'object') return s;
+            const sClean = { ...s };
+            // Remove UI IDs from series rows if they are local temporary IDs
+            if (typeof sClean.id === 'string' && sClean.id.startsWith('temp-')) {
+                delete sClean.id;
+            }
+            processObject(sClean);
+            return sClean;
+        });
+    }
+
+    if (cleaned.identifiers && Array.isArray(cleaned.identifiers)) {
+        cleaned.identifiers = cleaned.identifiers.map((i: any) => {
+            if (typeof i !== 'object') return i;
+            processObject(i);
+            return i;
+        });
+    }
+
+    return cleaned;
+}
+
+// Normalize numeric values from strings to numbers (for editing)
+export function normalizeItemData(item: Partial<Item>): Partial<Item> {
+    if (!item) return {};
+    
+    // Deep clone to avoid side effects
+    const normalized = JSON.parse(JSON.stringify(item));
+
+    const processNormalization = (obj: any) => {
+        if (!obj || typeof obj !== 'object' || Array.isArray(obj)) return;
+
+        Object.keys(obj).forEach(key => {
+            const containers = ['financial', 'quantity', 'customs', 'description', 'fa_data', 'reference'];
+            const isContainer = containers.includes(key);
+
+            if (NUMERIC_FIELDS.includes(key) && !isContainer) {
+                const val = obj[key];
+                if (val !== undefined && val !== null && val !== '') {
+                    const num = Number(val);
+                    if (!isNaN(num)) {
+                        obj[key] = num;
+                    }
+                }
+            }
+
+            if (isContainer && obj[key]) {
+                processNormalization(obj[key]);
+            }
+        });
+    };
+
+    // Process top level and nested objects
+    processNormalization(normalized);
+
+    // Ensure mandatory containers exist to allow binding and partial updates
+    const mandatoryContainers = ['financial', 'quantity', 'customs', 'description', 'fa_data', 'reference'];
+    mandatoryContainers.forEach(container => {
+        if (!normalized[container]) {
+            normalized[container] = {};
+        }
+    });
+
+    // Process arrays
+    if (normalized.series && Array.isArray(normalized.series)) {
+        normalized.series.forEach((s: any) => processNormalization(s));
+    } else {
+        normalized.series = [];
+    }
+    
+    if (normalized.identifiers && Array.isArray(normalized.identifiers)) {
+        normalized.identifiers.forEach((i: any) => processNormalization(i));
+    } else {
+        normalized.identifiers = [];
+    }
+
+    // 5. Popular campos de visualización para que el formulario los muestre al editar
+    if (normalized.part_number && !normalized.part_number_display) {
+        normalized.part_number_display = normalized.part_number;
+    }
+
+    if (normalized.unit_of_measure_code && !normalized.unit_code) {
+        normalized.unit_code = normalized.unit_of_measure_code;
+    }
+
+    if (normalized.customs?.origin_country && !normalized.origin_country_name) {
+        normalized.origin_country_name = normalized.customs.origin_country;
+    }
+
+    // 5. Popular campos de visualización para que el formulario los muestre al editar
+    if (normalized.part_number && !normalized.part_number_display) {
+        normalized.part_number_display = normalized.part_number;
+    }
+
+    if (normalized.unit_of_measure_code && !normalized.unit_code) {
+        normalized.unit_code = normalized.unit_of_measure_code;
+    }
+
+    if (normalized.customs && normalized.customs.origin_country && !normalized.origin_country_name) {
+        normalized.origin_country_name = normalized.customs.origin_country;
+    }
+
+    // Solo asegurar que el objeto description exista para que sea reactivo al editar
+    if (!normalized.description) {
+        normalized.description = {
+            description_spanish: normalized.part_description_es || '',
+            description_english: normalized.part_description_en || ''
+        };
+    } else {
+        // Sincronización bidireccional entre raíz (redundancia) y objeto anidado
+        const descES = normalized.description.description_spanish || normalized.part_description_es || '';
+        const descEN = normalized.description.description_english || normalized.part_description_en || '';
+        
+        normalized.description.description_spanish = descES;
+        normalized.description.description_english = descEN;
+        normalized.part_description_es = descES;
+        normalized.part_description_en = descEN;
+    }
+
+    return normalized;
+}
+
+export interface Item {
+    id?: number;
+    [key: string]: any;
+}
+
+// Helper function to check if an object has any meaningful values
+export function hasValues(obj: any): boolean {
+    if (!obj || typeof obj !== 'object') return false;
+    
+    // Si el objeto está intencionalmente vacío o tiene campos que serán usados,
+    // es mejor dejar que el backend valide si es requerido.
+    const values = Object.values(obj);
+    if (values.length === 0) return false;
+    
+    return values.some(
+        (val) =>
+            val !== undefined &&
+            val !== null &&
+            val !== '' &&
+            !(typeof val === 'object' && !hasValues(val))
+    );
+}
diff --git a/frontend/src/routes/dashboard/invoices/edit/[id]/+page.svelte b/frontend/src/routes/dashboard/invoices/edit/[id]/+page.svelte
index cebf8012..f04b8f3d 100644
--- a/frontend/src/routes/dashboard/invoices/edit/[id]/+page.svelte
+++ b/frontend/src/routes/dashboard/invoices/edit/[id]/+page.svelte
@@ -388,54 +388,63 @@
 		};
 	}
 
+	// Resolved defaults logic: check both ssisgen and qsisgen keys in the nested settings
+	const resolvedDefaults = $derived.by(() => {
+		// FIX: data.defaultSettings is already the settings object for this specific type
+		const settings = data.defaultSettings || {};
+		const ssisgen = settings.ssisgen || {};
+		const qsisgen = settings.qsisgen || {};
+		return { ...qsisgen, ...ssisgen };
+	});
+
 	// Referencias a los componentes de formulario para obtener sus datos
 	// Si estamos en modo edición (!data.isCreate) y tenemos una factura, usarla
-	// Si estamos en modo creación, usar defaultSettings
+	// Si estamos en modo creación, usar resolvedDefaults
 	let InvoiceTopFieldsFormData = $state<any>(
 		!data.isCreate && data.invoice
 			? mapInvoiceToTopFields(data.invoice)
-			: mergeDefaults(topFieldsSkeleton, data.defaultSettings?.InvoiceTopFieldsFormData)
+			: mergeDefaults(topFieldsSkeleton, resolvedDefaults.InvoiceTopFieldsFormData)
 	);
 	let generalFormData = $state<any>(
 		!data.isCreate && data.invoice
 			? mapInvoiceToGeneral(data.invoice)
-			: mergeDefaults(generalSkeleton, data.defaultSettings?.generalFormData)
+			: mergeDefaults(generalSkeleton, resolvedDefaults.generalFormData)
 	);
 	let observationFormData = $state<any>(
 		!data.isCreate && data.invoice
 			? mapInvoiceToObservations(data.invoice)
-			: mergeDefaults(observationSkeleton, data.defaultSettings?.observationFormData)
+			: mergeDefaults(observationSkeleton, resolvedDefaults.observationFormData)
 	);
 	let itemsFormData = $state<any>(
 		!data.isCreate && data.invoice
 			? mapInvoiceToItems(data.invoice)
-			: ensureItemsFormData(data.defaultSettings?.itemsFormData)
+			: ensureItemsFormData(resolvedDefaults.itemsFormData)
 	);
 	let othersFormData = $state<any>(
 		!data.isCreate && data.invoice
 			? mapInvoiceToOthers(data.invoice)
-			: mergeDefaults(othersSkeleton, data.defaultSettings?.othersFormData)
+			: mergeDefaults(othersSkeleton, resolvedDefaults.othersFormData)
 	);
 	let continuationFormData = $state<any>(
 		!data.isCreate && data.invoice
 			? mapInvoiceToContinuation(data.invoice)
-			: mergeDefaults(continuationSkeleton, data.defaultSettings?.continuationFormData)
+			: mergeDefaults(continuationSkeleton, resolvedDefaults.continuationFormData)
 	);
 
 	// Estados para saber si existen datos previos
 	let observationExists = $state(
-		!data.isCreate ? !!data.invoice : !!data.defaultSettings?.observationFormData
+		!data.isCreate ? !!data.invoice : !!resolvedDefaults.observationFormData
 	);
 	let itemsExists = $state(
 		!data.isCreate
 			? !!(data.invoice?.items && data.invoice.items.length > 0)
-			: !!data.defaultSettings?.itemsFormData?.items?.length
+			: !!resolvedDefaults.itemsFormData?.items?.length
 	);
 	let othersExists = $state(
-		!data.isCreate ? !!data.invoice : !!data.defaultSettings?.othersFormData
+		!data.isCreate ? !!data.invoice : !!resolvedDefaults.othersFormData
 	);
 	let continuationExists = $state(
-		!data.isCreate ? !!data.invoice : !!data.defaultSettings?.continuationFormData
+		!data.isCreate ? !!data.invoice : !!resolvedDefaults.continuationFormData
 	);
 
 	let calculatedExchangeRate = $state<number | null>(
@@ -885,6 +894,9 @@
 
 			if (!res.error && res.data) {
 				const settings = res.data.settings || {};
+				const ssisgen = settings.ssisgen || {};
+				const qsisgen = settings.qsisgen || {};
+				const combined = { ...qsisgen, ...ssisgen };
 
 				// Mark as loaded even if empty to prevent retries for the same combination
 				lastLoadedKey = currentKey;
@@ -895,13 +907,13 @@
 				// Re-apply merges with new defaults
 				InvoiceTopFieldsFormData = mergeDefaults(
 					topFieldsSkeleton,
-					settings.InvoiceTopFieldsFormData
+					combined.InvoiceTopFieldsFormData
 				);
-				generalFormData = mergeDefaults(generalSkeleton, settings.generalFormData);
-				observationFormData = mergeDefaults(observationSkeleton, settings.observationFormData);
-				itemsFormData = ensureItemsFormData(settings.itemsFormData);
-				othersFormData = mergeDefaults(othersSkeleton, settings.othersFormData);
-				continuationFormData = mergeDefaults(continuationSkeleton, settings.continuationFormData);
+				generalFormData = mergeDefaults(generalSkeleton, combined.generalFormData);
+				observationFormData = mergeDefaults(observationSkeleton, combined.observationFormData);
+				itemsFormData = ensureItemsFormData(combined.itemsFormData);
+				othersFormData = mergeDefaults(othersSkeleton, combined.othersFormData);
+				continuationFormData = mergeDefaults(continuationSkeleton, combined.continuationFormData);
 
 				// Ensure types remain as selected
 				InvoiceTopFieldsFormData.invoice_type =
diff --git a/frontend/src/routes/dashboard/invoices/settings/+page.server.ts b/frontend/src/routes/dashboard/invoices/settings/+page.server.ts
index 9228b1e0..852ba58b 100644
--- a/frontend/src/routes/dashboard/invoices/settings/+page.server.ts
+++ b/frontend/src/routes/dashboard/invoices/settings/+page.server.ts
@@ -118,6 +118,34 @@ export const load: PageServerLoad = async ({ cookies, fetch, url }) => {
         fetch
     );
 
+    const valuationMethodsPromise = authenticatedFetch(
+        'v1/public/reference_data/valuation-methods/?page=1&page_size=100',
+        {},
+        cookies,
+        fetch
+    );
+
+    const legendsPromise = authenticatedFetch(
+        `v1/a76/legends/?company_id=${companyId}&page=1&page_size=200`,
+        {},
+        cookies,
+        fetch
+    );
+
+    const sealsPromise = authenticatedFetch(
+        `v1/a76/seals/?company_id=${companyId}&page=1&page_size=100`,
+        {},
+        cookies,
+        fetch
+    );
+
+    const enclosuresPromise = authenticatedFetch(
+        'v1/public/reference_data/customs-warehouses/?page=1&page_size=100',
+        {},
+        cookies,
+        fetch
+    );
+
     const pedimentosPromise = authenticatedFetch(
         `v1/a76/pedimentos/?company_id=${companyId}&page=1&page_size=100`,
         {},
@@ -141,6 +169,10 @@ export const load: PageServerLoad = async ({ cookies, fetch, url }) => {
             customsSectionsResponse,
             codePedimentoRegimensResponse,
             transportModesResponse,
+            valuationMethodsResponse,
+            legendsResponse,
+            sealsResponse,
+            enclosuresResponse,
             pedimentosResponse
         ] = await Promise.all([
             invoiceTypesPromise,
@@ -157,6 +189,10 @@ export const load: PageServerLoad = async ({ cookies, fetch, url }) => {
             customsSectionsPromise,
             codePedimentoRegimensPromise,
             transportModesPromise,
+            valuationMethodsPromise,
+            legendsPromise,
+            sealsPromise,
+            enclosuresPromise,
             pedimentosPromise
         ]);
 
@@ -174,6 +210,10 @@ export const load: PageServerLoad = async ({ cookies, fetch, url }) => {
         const customsSections = customsSectionsResponse.ok ? await customsSectionsResponse.json() : { items: [] };
         const codePedimentoRegimens = codePedimentoRegimensResponse.ok ? await codePedimentoRegimensResponse.json() : { items: [] };
         const transportModes = transportModesResponse.ok ? await transportModesResponse.json() : { items: [] };
+        const valuationMethods = valuationMethodsResponse.ok ? await valuationMethodsResponse.json() : { items: [] };
+        const legends = legendsResponse.ok ? await legendsResponse.json() : { items: [] };
+        const seals = sealsResponse.ok ? await sealsResponse.json() : { items: [] };
+        const enclosures = enclosuresResponse.ok ? await enclosuresResponse.json() : { items: [] };
         const pedimentos = pedimentosResponse.ok ? await pedimentosResponse.json() : { items: [] };
 
         return {
@@ -191,6 +231,10 @@ export const load: PageServerLoad = async ({ cookies, fetch, url }) => {
             customsSections: customsSections.items || [],
             codePedimentoRegimens: codePedimentoRegimens.items || [],
             transportModes: transportModes.items || [],
+            valuationMethods: valuationMethods.items || [],
+            legends: legends.items || [],
+            seals: seals.items || [],
+            enclosure: enclosures.items || [],
             pedimentos: pedimentos.items || [],
             companyId
         };
diff --git a/frontend/src/routes/dashboard/invoices/settings/+page.svelte b/frontend/src/routes/dashboard/invoices/settings/+page.svelte
index ed0131d8..70e1869a 100644
--- a/frontend/src/routes/dashboard/invoices/settings/+page.svelte
+++ b/frontend/src/routes/dashboard/invoices/settings/+page.svelte
@@ -97,22 +97,18 @@
 	async function loadSettings() {
 		const cid = companyStore?.activeCompany?.id;
 		if (!selectedInvoiceType || !selectedOperationType || !cid) {
-			console.log('LOAD: Skipping - Missing Context', { selectedInvoiceType, selectedOperationType, cid });
 			return;
 		}
 		
 		const currentKey = `${selectedOperationType}:${selectedInvoiceType}:${cid}`;
 		if (currentKey === lastLoadedKey && !isLoading) {
-			console.log('LOAD: Skipping - Key match', currentKey);
 			return;
 		}
 		
 		if (isLoading) {
-			console.log('LOAD: Skipping - Already Loading');
 			return;
 		}
 		
-		console.log('LOAD: Starting...', currentKey);
 		isLoading = true;
 		try {
 			const res = await api.get(
@@ -122,7 +118,6 @@
 			if (res.status === 200 || res.data) {
 				const settingsData = res.data;
 				lastLoadedKey = currentKey; 
-				console.log('LOAD: Success', { hasSettings: !!settingsData?.settings });
 				if (settingsData && settingsData.settings) {
 					rawSettings = settingsData.settings;
 					applySettings(rawSettings);
@@ -131,7 +126,6 @@
 					resetForms();
 				}
 			} else {
-				console.log('LOAD: Response format mismatch or failed', res.status);
 				lastLoadedKey = currentKey;
 				rawSettings = {};
 				resetForms();
@@ -142,7 +136,6 @@
 			rawSettings = {};
 			resetForms();
 		} finally {
-			console.log('LOAD: Finished');
 			isLoading = false;
 		}
 	}
@@ -406,12 +399,14 @@
 		if (obj !== null && typeof obj === 'object') {
 			return Object.entries(obj).reduce((acc: any, [key, value]) => {
 				const cleaned = cleanObject(value);
-				if (
+				// Explicitly keep 0, 0.0, and false as they are common valid settings
+				const isValidValue =
 					cleaned !== null &&
 					cleaned !== undefined &&
 					cleaned !== '' &&
-					!(typeof cleaned === 'object' && Object.keys(cleaned).length === 0)
-				) {
+					!(typeof cleaned === 'object' && Object.keys(cleaned).length === 0);
+
+				if (isValidValue || cleaned === 0 || cleaned === false) {
 					acc[key] = cleaned;
 				}
 				return acc;
@@ -516,13 +511,11 @@
 
 	// Handle explicit changes
 	function handleOperationTypeChange(v: string) {
-		console.log('UI: Operation type change:', v);
 		selectedOperationType = v;
 		loadSettings();
 	}
 
 	function handleInvoiceTypeChange(v: string) {
-		console.log('UI: Invoice type change:', v);
 		selectedInvoiceType = v;
 		loadSettings();
 	}
@@ -659,9 +652,11 @@
 										{invoice}
 										bind:formData={observationFormData}
 										bind:exists={observationExists}
-										seals={[]}
+										seals={data.seals || []}
+										legends={data.legends || []}
+										valuationMethods={data.valuationMethods || []}
 										incoterms={data.incoterms || []}
-										enclosure={[]}
+										enclosure={data.enclosure || []}
 										operationType={operationTypeNumeric}
 										{invoiceType}
 										isSettings={true}