When a taxpayer should file an amended federal tax return

When a taxpayer realizes that their federal tax return has a math error, missing income or other mistake, they should file an amended tax return.

A taxpayer must file an amended return if they need to correct: 

• Filing status

• Income

• Deductions

• Credits

• Tax liability

Math errors and missing schedules
Taxpayers usually do not need to file an amended return to fix a math error or if they forgot to attach a form or schedule. The IRS will correct the math error while processing the tax return and notify the taxpayer by mail. The agency will send a letter to request any missing forms or schedules.

The IRS Interactive Tax Assistant can help taxpayers decide if an amended return is necessary
Taxpayers can use the Should I File an Amended Return? tool in the Interactive Tax Assistant on IRS.gov to help decide if they should file an amended return to correct an error or make other changes if they already filed.

How to file an amended tax return
Taxpayers should use Form 1040-X, Amended U.S. Individual Income Tax Return, to correct a previously filed Form 1040-series return or to change amounts previously adjusted by the IRS. Taxpayers can file Form 1040-X electronically for their 2020, 2021, 2022 and 2023 Forms 1040 or 1040-SR. Additionally, they can electronically amend Form 1040-NR and Form 1040-SS/PR for tax years 2021, 2022 and 2023.

Check the status of an amended return
Taxpayers can check the status of their Form 1040-X with the Where's My Amended Return online tool or by calling 866-464-2050 three weeks after filing it. They can also check the status of their refund with the Where’s My Refund tool.

When using either tool, taxpayers will need to enter their Social Security or Taxpayer Identification number along with their date of birth and ZIP code to prove their identity. Once authenticated, they can view the status of their amended return across three processing stages: received, adjusted and completed.

Some tax returns may take longer to process
The IRS issues most refunds in fewer than 21 days for taxpayers who filed electronically and chose direct deposit. Some returns have errors or need more review and may take longer to process.

More information
Form 1040-X, Amended U.S. Individual Income Tax Return, Frequently Asked Questions