Over Payment Refund Letter To Customers Template. Clearly state the decision regarding the refund.Refunds for EFiling (electronic filing) are made for overpayment or errors, not for filing against the wrong person or entity. We have identified the following overpayment and are in good faith voluntarily refunding all monies collected in error. Form TR210 is a letter you receive if: If you received it, you may be entitled to a refund for the tax year stated on the letter.