Question What should I do if I made a mistake on my federal return that I've already filed? Answer It depends on the type of mistake you made: Many mathematical errors are caught during the processing of the tax return and corrected by the IRS, so you may not need to correct these mistakes. If you didn't claim the correct filing status or you need to change your income, deductions, or credits, you should file an amended or corrected return using Form 1040-X, Amended U.S. Individual Income Tax Return. When filing an amended or corrected return: Include copies of any forms and/or schedules that you're changing or didn't include with your original return. To avoid delays, file Form 1040-X only after you've filed your original return. Generally, for a credit or refund, you must file Form 1040-X within 3 years after the date you filed your original return or within 2 years after the date you paid the tax, whichever is later. If you file an amended or corrected return before the due date for the original return, the amended return will replace or supersede the original return. Filing a superseding return and paying any additional taxes owed may allow you to avoid interests or penalties. Allow 8 to 12 weeks for your amended return to be processed; however, in some cases, processing can take up to 16 weeks. For current processing status, check our processing status dashboard. Additional Information Tax Topic 308 — Amended returns Should I file an amended return? Instructions for Form 1040-X, Amended U.S. Individual Income Tax Return Form 1040-X frequently asked questions Category IRS procedures Sub-Category Amended returns & Form 1040X