What Is Form 1040X: Amended U.S. Individual Income Tax Return?

Form 1040X: Amended U.S. Individual Income Tax Return is issued by the Internal Revenue Service (IRS) to taxpayers who need to amend their tax returns for any reason.

According to the IRS website, even the government understands that mistakes happen, which is why the form exists in the first place. However, it’s important to avoid using Form 1040X for mathematic errors in your tax return; the IRS will correct any in your return. Form 1040X, on the other hand, is necessary for amendments to your tax return that will change tax calculation, such as changes to filing status, number of dependents, or corrections to income credits or deductions.

Who Can File Form 1040X: Amended U.S. Individual Income Tax Return?

This form should be filed by anyone who has already filed a tax return and would like to do the following:

  • Correct Forms 1040, 1040-A, 1040-EZ, 1040-NR, or 1040-NR EZ
  • Make elections after the prescribed deadline
  • Change any amounts previously adjusted by the IRS
  • Make a claim for a carryback due to a loss or unused credit

In order to receive a credit, taxpayers must file Form 1040X within three years after the original return was filed or within two years after the tax was paid, whichever is later.

How to File Form 1040X: Amended U.S. Individual Income Tax Return

This form is an itemized, line-by-line description of all necessary adjustments, so the taxpayer can clearly record the exact type and amount of each amendment and give a brief description of what is being amended and why.

The IRS provides the following tips to taxpayers about Form 1040X:

  • Wait for the first refund. If your original tax return included a refund, you should wait until you receive it before filing Form 1040X. The IRS will issue a separate, second refund if it is warranted, so you are free to cash the first check.
  • File Form 1040X within the three-year amendment time period. If your change will affect your refund amount, you must file the form within three years from the date of your original tax return or within two years from the date of paying the tax amount, whichever is later. Any returns filed early will be considered filed on the official due date of tax season, generally April 15 of the calendar year.

The IRS requires filers to provide a copy of the return being amended as well as any notices about adjustments to that return.

[Important: In most cases, taxpayers who file Form 1040X must also amend their state tax returns.]

Download Form 1040X: Amended U.S. Individual Income Tax Return

Click this link to download a copy of Form 1040X: Amended U.S. Individual Income Tax Return.

Key Takeaways

  • Form 1040X is filed by taxpayers who need to amend their tax returns.
  • The form must be filed within three years after the original return was filed or within two years after the tax was paid, whichever is later.
  • Anyone who files Form 1040X may also need to amend their state tax return.