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. We have identified the following overpayment and are in good faith voluntarily refunding all monies collected in error. The salary overpayment resulted because . This memorandum serves as notification of an overpayment of wages that you received and the subsequent repayment that is your responsibility. Create a payment refund letter format tailored to your needs. Example: A customer purchases one taxable item and takes delivery in a county that does not impose a discretionary sales surtax.