If you discover an error after filing your return, you may need to amend your return. The IRS may correct errors in math on a return and may accept returns without certain forms or schedules. In these instances, there is no need to amend your return! However, do file an amended return if there is a change in your filing status, income, deductions, or credits. Also, if the Form 8938 (PDF), Statement of Specified Foreign Financial Assets, applies to you, the form must be filed with an annual return or an amended return. See When and How To File in the Form 8938 Instructions (PDF).

Use Form 1040X (PDF), Amended U.S. Individual Income Tax Return, to correct a previously filed Form 1040 (PDF), Form 1040A(PDF), Form 1040EZ (PDF), Form 1040NR (PDF) or Form 1040NR-EZ (PDF). You cannot file an amended tax return electronically under the e-file system. See Where To File in the Form 1040X Instructions (PDF) for the address to mail your amended return.

If you owe additional tax for a tax year for which the due date for filing has not passed, file Form 1040X and pay the tax by the due date for that year (without regard to any extension of time to file) to avoid penalties and interest. If the due date falls on a Saturday, Sunday, or legal holiday, filing the form and paying the tax is timely if filed or paid the next business day.

Generally, to claim a refund, you must file Form 1040X 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. Returns filed before the due date (without regard to extensions) are considered filed on the due date.

File a separate Form 1040X for each tax year you are amending. Mail each form in a separate envelope. Be sure to enter the year of the return you are amending at the top of Form 1040X. The form has three columns:

  • Column A shows original figures (the original return) or adjusted figures (prior amendments or exam changes).
  • Column C shows the corrected figures (what they should be).
  • Column B is the difference between Columns A and C. There is an area on the back of the form to explain the specific changes you are making and the reason for each change.

Attach copies of any forms or schedules affected by the change including any Form(s) W-2. You should also attach Form(s) 1099 if received after the original return filing and there is income tax withheld.

You can check the status of your Form 1040X (PDF) using the Where’s My Amended Return? (WMAR) online tool or 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.

You must enter your taxpayer identification number (usually your Social Security number), date of birth, and ZIP code in either tool to prove your identity. Once you authenticate, the Web tool shows an illustrated graphic to visually communicate the status of your amended return within the processing stages: Received, Adjusted, or Completed. As a reminder, amended returns take up to 16 weeks to process and up to three weeks to show up in our system. Before that time, there is no need to call the IRS unless the tool specifically tells you to do so.

Please note: A change made on your federal return may affect your state tax liability. For information on how to correct your state tax return, contact your state tax agency.

Forms are available online at IRS.gov or by calling 800-TAX-FORM (800-829-3676).

How To Fix A Mistake On Your Tax Return