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

The 1040-X, Amended U.S. Individual U.S. Income Tax Return is a form used by taxpayers who need to correct an error in a previously filed federal tax return. Common mistakes corrected with this form include errors in the taxpayer's filing status or number of dependents or omissions of credits or deductions. Form 1040-X should not be used to correct simple mathematical errors in a tax return, as the Internal Revenue Service (IRS) routinely corrects such mistakes while processing returns.

Who Can File Form 1040-X?

A 1040-X form should be filed by anyone who has already filed a tax return and needs to amend it for any of the following reasons:

• To correct Form 1040, 1040-SR, or 1040-NR. Most taxpayers use one of these three forms to file their annual tax returns.
• To make an election after the deadline. For example, a married taxpayer can elect to file as an individual or jointly with a spouse.
• To change an amount that was previously adjusted by the IRS
• To make a claim for a carryback due to a loss or unused credit

All pages of form 1040-X can be found .

How to File Form 1040-X

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

The filer must include not only the 1040-X but a revised version of the entire 1040 or 1040-SR, including any attached forms and schedules, even if they were not amended. Taxpayers can e-file a Form 1040-X or send it to the IRS by mail. Form 1040-X can only be filed after an annual return is filed. Be sure to include the following documents with your amended return:

• Income-related forms that were not submitted, such as W-2s or 1099s
• Documents or forms that support your amended income tax return

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

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

• Wait for the first refund, if you were due one. If your original tax return included a refund, you should wait until you get it before filing Form 1040-X. The IRS will issue a separate, second refund if it is warranted, so feel free to cash the first check.
• File a 1040-X form within the three-year amendment eligibility period. If the 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 deadline date for filing taxes, which is usually April 15 of the calendar year.

What Are the Benefits of Filing Form 1040-X?

When you file 1040-X, be sure you look out for anything that you missed, such as exemptions, deductions, and credits. It may seem daunting and you may feel as though you'll be penalized for having to correct any errors. But there are advantages that come with amending your income tax return, including:

• Claiming additional tax credits
• Taking additional deductions
• Getting a (bigger) refund

Keep in mind that you may also have to report additional income that you didn't include on your original return. If this happens, your taxable income will increase and you may have a balance owing. This means you are responsible for paying the outstanding amount plus any fees and penalties that may apply.

The Bottom Line

Form 1040-X is used by taxpayers to amend their previously filed tax returns (Form 1040) in order to correct errors or update information. The form requires taxpayers to provide details about the changes being made, along with an explanation for the amendments.