diff --git a/api.py b/api.py
index a3b9ce9..a036707 100644
--- a/api.py
+++ b/api.py
@@ -383,8 +383,8 @@ class ClientCreateRequest(BaseModel):
         description="Nom du client (CT_Intitule) - OBLIGATOIRE"
     )
     
-    numero: Optional[str] = Field(
-        None, 
+    numero: str = Field(
+        ..., 
         max_length=17, 
         description="Numéro client CT_Num (auto si None)"
     )