How long do I have to file an appeal to an overpayment determination? July 21, 2021 16:49 Updated The appeal must be filed within thirty days from the date the overpayment determination was mailed. Related articles How do I file an appeal to an overpayment determination? What can I expect after I file my appeal? How long does it take to review an unemployment benefits case? Important Information It says I have a pending issue online. What does that mean?