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.We have identified the following overpayment and are in good faith voluntarily refunding all monies collected in error. Our document template is designed to make the process of writing an "Inform a Customer of an Overpayment" letter quick, easy, and stress-free. An overpayment is caused when Texas Workforce Commission (TWC) pays unemployment benefits that you were not eligible to receive.