2 The complete amount of the overpayment is the difference between the gross amount paid and the gross amount that was due to the employee. In any event, applications can only be considered if filed within three years of the date of overpayment.Rules and regulations help taxpayers understand the City's administration of the income tax ordinance. The County Treasurer typically applies overpayments related to a decreased value as a credit on the next tax bill rather than issuing a refund check. There are certain federal laws that give employers the ability to recover overpaid wages from their employees. Fill out the Form 10A to apply for a refund. Separate 10As must be completed for each W-2 or each RITA Municipality.