diff --git a/app/api/services/provide_loan.py b/app/api/services/provide_loan.py
index 61b2a16..f09cd31 100644
--- a/app/api/services/provide_loan.py
+++ b/app/api/services/provide_loan.py
@@ -64,6 +64,9 @@ class ProvideLoanService(BaseService):
 
                     if(amount < transaction_offer.min_amount):
                         return ResponseHelper.error(result_description="The amount is less than the minimum allowed transaction amount.")
+                    elif amount > transaction_offer.max_amount:
+                        return ResponseHelper.error(result_description="The amount is greater than the maximum allowed transaction amount.")
+
                     
                     # transaction_offer_id =  int(offer_id[5:]) # The last part is int
 
diff --git a/app/models/customer.py b/app/models/customer.py
index 883d34f..1469dad 100644
--- a/app/models/customer.py
+++ b/app/models/customer.py
@@ -50,6 +50,8 @@ class Customer(db.Model):
             raise ValueError("Customer already exists")
         elif Account.query.filter_by(id=account_id).first():
             raise ValueError("Account already exists")
+        elif cls.query.filter_by(msisdn=msisdn).first():
+            raise ValueError("msisdn already exists")
         
         # Create the customer
         customer = cls(