Amended returns & Form 1040X

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.

• 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

Since the IRS didn't catch your mistake during processing, you should:

• File an amended return using Form 1040-X, Amended U.S. Individual Income Tax Return as soon as possible.
• Include any forms and/or schedules that you're changing and/or didn't include with the original return.
• Return the refund check with a letter of explanation. Write "Void" in the endorsement section of the check when you return it.
• Don't staple, bend, or paper clip the check.
• When your amended return has completed processing, the IRS will issue a new refund check.
• 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.

• Should I file an amended return?
• Instructions for Form 1040-X, Amended U.S. Individual Income Tax Return
• Tax Topic 308 - Amended returns
• Tax Topic 161 - Returning an erroneous refund – Paper check or direct deposit
• Form 1040-X frequently asked questions

You can check the status of your Form 1040-X, Amended U.S. Individual Income Tax Return using the Where's My Amended Return? online tool or by calling the toll-free telephone number 866-464-2050 three weeks after you file your amended return. Both tools are available in English and Spanish and track the status of amended returns for the current year and up to three prior years.

When using either tool, you must enter your taxpayer identification number, such as your Social Security number, along with your date of birth, and ZIP code to prove your identity. Once authenticated, you can view the status of your amended return across three processing stages -- Received, Adjusted, and Completed.

The online tool includes an illustrated graphic that visually communicates where your amended return resides within the processing stages. Allow 8 to 12 weeks for your amended return to be processed; however, in some cases, processing can take up to 16 weeks. It can take up to three weeks after filing it to show up in our system. There’s no need to call the IRS during that three-week period unless the tool specifically tells you to do so. For current processing status, check our processing status dashboard.

• Tax Topic 308 — Amended returns
• Form 1040-X frequently asked questions