diff --git a/backend/api/v1/modules/a76/general_catalogs/units_of_measure/dto.py b/backend/api/v1/modules/a76/general_catalogs/units_of_measure/dto.py
index aa75c493..56c9d37f 100644
--- a/backend/api/v1/modules/a76/general_catalogs/units_of_measure/dto.py
+++ b/backend/api/v1/modules/a76/general_catalogs/units_of_measure/dto.py
@@ -30,7 +30,7 @@ class UnitOfMeasureBase(BaseModel):
     code: str = Field(..., max_length=20, description="Unit Code")
     description: Optional[str] = Field(None, max_length=100)
     description_en: Optional[str] = Field(None, max_length=100)
-    customs_code: Optional[str] = Field(None, max_length=20)
+    customs_code: Optional[int] = Field(None)
     american_code: Optional[str] = Field(None, max_length=20)
     ace_code: Optional[str] = Field(None, max_length=20)
     oma_code: Optional[str] = Field(None, max_length=20)
@@ -42,7 +42,7 @@ class UnitOfMeasureGeneralBase(BaseModel):
     conversion_factor: Optional[Decimal] = None
     mexico_unit: Optional[str] = Field(None, max_length=20)
     american_unit_code: Optional[str] = Field(None, max_length=20)
-    customs_code: Optional[str] = Field(None, max_length=20)
+    customs_code: Optional[int] = Field(None)
     ace_code: Optional[str] = Field(None, max_length=20)
 
 # --- Create DTOs ---
@@ -99,7 +99,7 @@ class UnitOfMeasureUpdate(BaseModel):
     code: Optional[str] = Field(None, max_length=20)
     description: Optional[str] = Field(None, max_length=100)
     description_en: Optional[str] = Field(None, max_length=100)
-    customs_code: Optional[str] = Field(None, max_length=20)
+    customs_code: Optional[int] = Field(None)
     american_code: Optional[str] = Field(None, max_length=20)
     ace_code: Optional[str] = Field(None, max_length=20)
     oma_code: Optional[str] = Field(None, max_length=20)
@@ -111,7 +111,7 @@ class UnitOfMeasureGeneralUpdate(BaseModel):
     conversion_factor: Optional[Decimal] = None
     mexico_unit: Optional[str] = Field(None, max_length=20)
     american_unit_code: Optional[str] = Field(None, max_length=20)
-    customs_code: Optional[str] = Field(None, max_length=20)
+    customs_code: Optional[int] = Field(None)
     ace_code: Optional[str] = Field(None, max_length=20)
 
 # --- Response DTOs ---