To manually report an overpayment claim or to report an offset due to a restored benefit on a case with an existing claim. There has been an error in your favor!The auditor will be looking for tax underpayments, overpayments and credits already taken for the items in the refund request. Type a letter to the person who made the payment, explaining that he paid in excess of the amount due. The salary overpayment resulted because . How to correct a payroll overpayment Step 1: Identify the cause of the error. Step 2: Calculate the overpayment amount.