How long do I have to file an appeal to an overpayment determination? July 21, 2021 20:45 Updated The appeal must be filed within thirty days from the date the overpayment determination was mailed. Related articles What if I disagree with the overpayment determination? How do I file an appeal to an overpayment determination? What can I expect after I file my appeal? What happens if I am overpaid? Will I be able to collect regular unemployment if I have an existing overpayment? Can you waive the fraud penalties on my overpayment?