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. The salary overpayment resulted because . Clearly state the decision regarding the refund. This will involve calmly explaining to them that you have paid an excess amount in comparison to the invoice received. Providers have the option to submit a Request For Extended Repayment Schedule (ERS). A complete ERS request should be submitted immediately. Use the sample letter at .