diff --git a/backend/api/v1/modules/core/users/service.py b/backend/api/v1/modules/core/users/service.py
index 3adb4782..f34474bc 100644
--- a/backend/api/v1/modules/core/users/service.py
+++ b/backend/api/v1/modules/core/users/service.py
@@ -142,6 +142,11 @@ class UserService:
             .scalar()
         )
 
+        # max_users=NULL en BD indica licencia sin cuota (ilimitada).
+        # Comparar con None lanzaría TypeError — salida temprana explícita.
+        if license.max_users is None:
+            return
+
         if active_users >= license.max_users:
             raise HTTPException(
                 status_code=403,