The notice will provide the tax type from which the overpayment originated and tax type to which it is being applied. CP268 tells you we made changes to your return because we believe there is a miscalculation on your return.Go to your message center, and look for a message with the subject "Notice of Determination Overpayment Waiver. Get free tax help from the IRS. File your taxes, get help preparing your return, help yourself with our online tools, find your local office – or call us. (2) Overpayment of interest or penalty. The IRS efforts to correct unemployment compensation overpayments will help most of the affected taxpayers avoid filing an amended tax return.