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.A refund letter to a customer should be structured to convey the necessary information clearly, empathetically, and respectfully. The salary overpayment resulted because . Please remember to fill out the middle portion of the application. You must include the property identification number of the erroneously paid parcel as well. We have identified the following overpayment and are in good faith voluntarily refunding all monies collected in error. This memorandum serves as notification of an overpayment of wages that you received and the subsequent repayment that is your responsibility.