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 . Let her know she overpaid you and that she can deduct the amount in the next pay check. Doing so you are highlighting your credibility. Medicare's notice of overpayment is also known as a "refund" or "demand" letter. An overpayment letter that says my benefits will be withheld starting April 2024, however the online account says my benefits are on hold now. NOTICE OF FOOD STAMP OVERPAYMENT (DEMAND LETTER) (Timely and Adequate). NOTICE.