diff --git a/backend/alembic/versions/g1b2c3d4e5f6_invoice_header_user_field_length.py b/backend/alembic/versions/g1b2c3d4e5f6_invoice_header_user_field_length.py
new file mode 100644
index 00000000..e37c00b9
--- /dev/null
+++ b/backend/alembic/versions/g1b2c3d4e5f6_invoice_header_user_field_length.py
@@ -0,0 +1,53 @@
+"""increase invoice_header who_processed and capture_user to 100 chars
+
+Revision ID: g1b2c3d4e5f6
+Revises: f7a8b9c0d1e2
+Create Date: 2026-04-30 00:00:00.000000
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision = 'g1b2c3d4e5f6'
+down_revision = 'f7a8b9c0d1e2'
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.alter_column(
+        'invoice_header',
+        'who_processed',
+        existing_type=sa.String(length=20),
+        type_=sa.String(length=100),
+        existing_nullable=True,
+        schema='a76',
+    )
+    op.alter_column(
+        'invoice_header',
+        'capture_user',
+        existing_type=sa.String(length=20),
+        type_=sa.String(length=100),
+        existing_nullable=True,
+        schema='a76',
+    )
+
+
+def downgrade() -> None:
+    op.alter_column(
+        'invoice_header',
+        'capture_user',
+        existing_type=sa.String(length=100),
+        type_=sa.String(length=20),
+        existing_nullable=True,
+        schema='a76',
+    )
+    op.alter_column(
+        'invoice_header',
+        'who_processed',
+        existing_type=sa.String(length=100),
+        type_=sa.String(length=20),
+        existing_nullable=True,
+        schema='a76',
+    )
diff --git a/backend/api/v1/modules/a76/invoices/models.py b/backend/api/v1/modules/a76/invoices/models.py
index e4e7c086..8cf823e6 100644
--- a/backend/api/v1/modules/a76/invoices/models.py
+++ b/backend/api/v1/modules/a76/invoices/models.py
@@ -124,10 +124,10 @@ class InvoiceHeader(Base, TenantScopedMixin, TimestampMixin):
         TIMESTAMP(timezone=False)
     )  # FECHAACTUALIZACION / FECHAACTUAL
     who_processed: Mapped[Optional[str]] = mapped_column(
-        String(20)
+        String(100)
     )  # USUARIOACT / Quien actualizó
     capture_user: Mapped[Optional[str]] = mapped_column(
-        String(20)
+        String(100)
     )  # USUARIOCAP / Usuario que capturó
 
     traffic_light_status: Mapped[Optional[str]] = mapped_column(
diff --git a/backend/api/v1/modules/a76/invoices/schemas.py b/backend/api/v1/modules/a76/invoices/schemas.py
index e8df1724..70f3382e 100644
--- a/backend/api/v1/modules/a76/invoices/schemas.py
+++ b/backend/api/v1/modules/a76/invoices/schemas.py
@@ -73,8 +73,8 @@ class InvoiceHeaderBase(BaseModel):
                 return InvoiceStatus.PROCESSED.value
         return v
     processed_date: Optional[datetime] = Field(None, description="Update date")
-    who_processed: Optional[str] = Field(None, max_length=20, description="Who processed")
-    capture_user: Optional[str] = Field(None, max_length=20, description="Capture user")
+    who_processed: Optional[str] = Field(None, max_length=100, description="Who processed")
+    capture_user: Optional[str] = Field(None, max_length=100, description="Capture user")
     traffic_light_status: Optional[str] = Field(
         None, max_length=50, description="Traffic light status"
     )