Amended U.S. Individual Income Tax Return, Form 1040-X

The Amended U.S. Individual Income Tax Return, also known as Form 1040-X or 1040X, is a document used to correct errors or omissions on your previously filed federal income tax return. This allows you to adjust your income, deductions, credits, and ultimately your tax liability.

Who should use it?

Use Form 1040-X if you discover any of the following after filing your original return:

  • Made a mistake: This includes errors in income reporting, deductions claimed, credits missed, or filing status.
  • Received updated information: Perhaps you received a W-2 correction or other document affecting your tax situation.
  • Missed deductions or credits: You may have overlooked eligible deductions or credits that you qualify for.
  • Claiming a carryback: If you have significant losses or unused credits, you can claim them retroactively to reduce taxes in previous years.

Need to correct your tax return? Here are the steps to file an amended tax return.

What can be amended?

Form 1040-X allows you to amend various aspects of your return:

  • Income: Correct wages, interest, dividends, or other income amounts.
  • Deductions: Claim missed deductions for charitable donations, medical expenses, or other qualified items.
  • Credits: Add qualifying credits you initially missed, such as the Earned Income Tax Credit or Child Tax Credit.
  • Filing status: Change your filing status from single to married, head of household, or vice versa (restrictions apply).
  • Dependents: Add or remove dependents you mistakenly included or excluded.

What cannot be amended?

  • Filing status: Generally, you cannot change from "married filing jointly" to "married filing separately" after the due date.
  • Tax year: You cannot amend a return for a different tax year than the one you are correcting.

Things to remember:

  • Supporting documentation: Attach any relevant documents supporting your corrections or claims.
  • Error type: Not all errors require an amended return. Minor math errors might be corrected by the IRS automatically.
  • Deadline: Generally, file Form 1040-X within 3 years of the original return's due date (including extensions).
  • State amendments: If your federal return error impacts your state taxes, you may need to file a separate state tax amendment.

Form 1040-X Filing options:

  • Electronically: Available for 2019 and later Forms 1040 and 1040-SR, and 2021 and later Forms 1040-NR using tax filing software.
  • Paper: Mail completed Form 1040-X with any necessary schedules to the IRS address listed in the instructions.