diff --git a/backend/api/v1/modules/a76/classes/dto.py b/backend/api/v1/modules/a76/classes/dto.py
index 68054f2a..b8047e2f 100644
--- a/backend/api/v1/modules/a76/classes/dto.py
+++ b/backend/api/v1/modules/a76/classes/dto.py
@@ -221,6 +221,10 @@ class ClassWithFADataResponse(BaseModel):
     
     # FA-specific fields (embedded from a24.fa_classes)
     fa_class_id: Optional[int] = None
+    import_tariff_code: Optional[str] = None
+    import_tariff_type: Optional[str] = None
+    export_tariff_code: Optional[str] = None
+    export_tariff_type: Optional[str] = None
     depreciation_rate: Optional[Decimal] = None
     fda_code: Optional[str] = None
     eccn_code: Optional[str] = None
diff --git a/backend/api/v1/modules/a76/classes/service.py b/backend/api/v1/modules/a76/classes/service.py
index 4decee1c..904adddf 100644
--- a/backend/api/v1/modules/a76/classes/service.py
+++ b/backend/api/v1/modules/a76/classes/service.py
@@ -150,6 +150,10 @@ class ClassService:
                 "updated_at": base_class.updated_at,
                 # FA extension fields (None if no FA record exists)
                 "fa_class_id": fa_class.id if fa_class else None,
+                "import_tariff_code": fa_class.import_tariff_code if fa_class else None,
+                "import_tariff_type": fa_class.import_tariff_type if fa_class else None,
+                "export_tariff_code": fa_class.export_tariff_code if fa_class else None,
+                "export_tariff_type": fa_class.export_tariff_type if fa_class else None,
                 "depreciation_rate": fa_class.depreciation_rate if fa_class else None,
                 "fda_code": fa_class.fda_code if fa_class else None,
                 "eccn_code": fa_class.eccn_code if fa_class else None,
diff --git a/backend/api/v1/modules/a76/general_catalogs/fractions/us_tariff_fractions/service.py b/backend/api/v1/modules/a76/general_catalogs/fractions/us_tariff_fractions/service.py
index 877dfcc5..25894e11 100644
--- a/backend/api/v1/modules/a76/general_catalogs/fractions/us_tariff_fractions/service.py
+++ b/backend/api/v1/modules/a76/general_catalogs/fractions/us_tariff_fractions/service.py
@@ -100,9 +100,9 @@ class USTariffFractionService:
                 limit=limit
             )
             
-            # If Sitar returns empty list AND we didn't have specific filters, attempt fallback
-            if not sitar_items and not has_filters:
-                 logger.warning("Sitar return empty list for USA broad query. Attempting fallback to local DB.")
+            # If Sitar returns empty list, attempt fallback to local DB
+            if not sitar_items:
+                 logger.info(f"Sitar returned no results for USA query (filters={has_filters}). Attempting fallback to local DB.")
                  return USTariffFractionService._get_all_local(db, tenant_id, company_id, skip, limit, filters)
 
             # Map items
diff --git a/frontend/src/lib/api.ts b/frontend/src/lib/api.ts
index aed649d2..baa8f75c 100644
--- a/frontend/src/lib/api.ts
+++ b/frontend/src/lib/api.ts
@@ -270,7 +270,7 @@ async function fetchApi<T = any>(
 			}
 
 			return {
-				error: data.message || data.detail || 'Error en la petición',
+				error: data.message || (typeof data.detail === 'string' ? data.detail : JSON.stringify(data.detail)) || 'Error en la petición',
 				status: response.status
 			};
 		}
diff --git a/frontend/src/lib/components/dashboard/goods/classes/forms/FixedAssetClassForm.svelte b/frontend/src/lib/components/dashboard/goods/classes/forms/FixedAssetClassForm.svelte
index fb406f32..d5578a0c 100644
--- a/frontend/src/lib/components/dashboard/goods/classes/forms/FixedAssetClassForm.svelte
+++ b/frontend/src/lib/components/dashboard/goods/classes/forms/FixedAssetClassForm.svelte
@@ -541,7 +541,7 @@
 				class="uppercase {validationErrors.class_code
 					? 'border-red-500 focus-visible:ring-red-500'
 					: ''}"
-				maxlength={20}
+				maxlength={8}
 				oninput={() => {
 					if (validationErrors.class_code) {
 						const errors = { ...validationErrors };
diff --git a/frontend/src/routes/dashboard/goods/fixed-asset-classes/+page.svelte b/frontend/src/routes/dashboard/goods/fixed-asset-classes/+page.svelte
index 5a0af337..35ccccde 100644
--- a/frontend/src/routes/dashboard/goods/fixed-asset-classes/+page.svelte
+++ b/frontend/src/routes/dashboard/goods/fixed-asset-classes/+page.svelte
@@ -14,6 +14,10 @@
 	// Tipo extendido que combina A76Class y FAClass
 	interface FixedAssetClassExtended extends A76Class {
 		fa_class_id?: number;
+		import_tariff_code?: string | null;
+		import_tariff_type?: string | null;
+		export_tariff_code?: string | null;
+		export_tariff_type?: string | null;
 		depreciation_rate?: number | null;
 		fda_code?: string | null;
 		eccn_code?: string | null;
@@ -578,6 +582,10 @@
 													  cleanData.depreciation_rate != null
 													? Number(cleanData.depreciation_rate)
 													: null,
+										import_tariff_code: cleanData.import_tariff_code || null,
+										import_tariff_type: cleanData.import_tariff_type || null,
+										export_tariff_code: cleanData.export_tariff_code || null,
+										export_tariff_type: cleanData.export_tariff_type || null,
 										fda_code: (cleanData.fda_key ?? cleanData.fda_code) || null,
 										eccn_code: cleanData.eccn_code || null
 									},