diff --git a/Models/Repositories/PhSCustomerRepository.cs b/Models/Repositories/PhSCustomerRepository.cs
index 64607d0..c8456b0 100644
--- a/Models/Repositories/PhSCustomerRepository.cs
+++ b/Models/Repositories/PhSCustomerRepository.cs
@@ -51,10 +51,11 @@ namespace Models.Repositories
 
             if (!string.IsNullOrWhiteSpace(document))
             {
+                var loweredDoc = document.ToLower();
                 query = query.Where(c =>
                     c.PhSCustomerDocuments.Any(a =>
-                        a.DocumentNumber.ToLower().Contains(document)));            }
-
+                        a.DocumentNumber.Contains(loweredDoc))); // sin ToLower() acá
+            }
             if (!string.IsNullOrWhiteSpace(email))
             {
                 var loweredEmail = email.ToLower();