First, you need to issue a check to your customer using the Accounts Receivable account for the overpayment amount. We have identified the following overpayment and are in good faith voluntarily refunding all monies collected in error.Any unearned funds must be returned. In this article, we'll show you how to write a refund request letter template that not only grabs attention but also persuades companies to act in your favor. If you do not request a fair hearing, or you lose the fair hearing, the overpayment decision will become final and you will be responsible for paying it back.