diff --git a/app/models/customer.py b/app/models/customer.py
index 1469dad..0a3c1e3 100644
--- a/app/models/customer.py
+++ b/app/models/customer.py
@@ -47,11 +47,11 @@ class Customer(db.Model):
     @classmethod
     def create_customer(cls, id, msisdn, country_code, account_id, account_type='savings'):
         if cls.query.filter_by(id=id).first():
-            raise ValueError("Customer already exists")
+            raise ValueError("Customer ID '{id}' already exists.")
         elif Account.query.filter_by(id=account_id).first():
-            raise ValueError("Account already exists")
+            raise ValueError(f"Account ID '{account_id}' already exists.")
         elif cls.query.filter_by(msisdn=msisdn).first():
-            raise ValueError("msisdn already exists")
+            raise ValueError("MSISDN '{msisdn}'  already exists")
         
         # Create the customer
         customer = cls(