This brief but important letter notifies a customer that he or she has overpaid you. It can serve as a very good customer relations letter.Our document template is designed to make the process of writing an "Inform a Customer of an Overpayment" letter quick, easy, and stress-free. Here's a sample to help you write a complaint letter about a product or service. The salary overpayment resulted because . Our service provides various examples of refund letters, including sample overpayment letters, refund request letters, and more.