If you discover an error or need to make changes after filing your tax return, you may need to file an amended return. This article covers everything from start to finish: when you need to amend, what Form 1040-X is, what happens after you file, and how to check your status.
What Is an Amended Tax Return?
An amended tax return is a correction to a tax return that has already been filed and accepted by the IRS or your state tax authority.
For federal returns, amendments are filed using Form 1040-X, Amended U.S. Individual Income Tax Return. This form lets you update information that affects your refund or balance due.
Important: If your original return hasn't been accepted yet, don't file an amendment. Wait until it's accepted before making corrections.
When Should I Amend My Return?
Amend your return if information was incorrect, incomplete, or changed after you filed. Common reasons include:
- Receiving a tax document after filing, such as a W-2, 1099, or Schedule K-1
- Correcting income that was reported incorrectly
- Adding or removing a dependent
- Changing your filing status
- Claiming deductions or credits you missed
- Correcting withholding amounts
- Updating education-related credits
You Usually Don't Need to Amend For:
- Simple math errors (the IRS typically corrects these)
- Certain processing errors
- IRS corrections that have already been made
- Missing informational schedules
- IRS notices simply requesting clarification
If you're not sure whether you need to amend, check the IRS notice you received or talk to a tax professional.
What Is Form 1040-X?
Form 1040-X shows:
- The amounts on your original return
- The changes you're making
- The corrected amounts
- An explanation for the amendment
You can use it to correct income, filing status, dependents, credits, deductions, withholding, and refund or balance-due amounts.
What Documents Do I Need?
This depends on what you're changing. Common examples:
- Form W-2 or 1099
- Schedule K-1
- Credit-related forms and schedules
- Any document that supports the change you're making
If you're mailing your amendment, include any required supporting forms and schedules.
When Is the Deadline to Amend?
To claim an additional refund, the IRS generally requires Form 1040-X to be filed within:
- 3 years from the date you filed your original return, or
- 2 years from the date you paid the tax —
whichever is later.
If you owe additional tax, file and pay as soon as possible to limit interest and penalties.
What Happens After I File?
- The IRS receives your amended return.
- The IRS reviews the changes and any supporting documentation.
- Any adjustments are made to your tax account.
- The IRS determines whether you're due an additional refund or owe additional tax.
Amended returns take longer to process than original returns — typically 8 to 12 weeks, and sometimes up to 16 weeks. Processing can take longer if the return:
- Has errors or is incomplete
- Isn't signed
- Is returned to you for more information
- Includes a Form 8379, Injured Spouse Allocation
- Is affected by identity theft or fraud
- Needs review by a specialized area, the bankruptcy area, or an appeals office
The IRS will contact you directly if they need more information.
Note: Filing an amended return does not speed up or affect the status of your original return.
How Do I Check My Amended Return's Status?
Use the IRS Where's My Amended Return? tool. You'll need:
- Your Social Security number
- Date of birth
- ZIP code
The tool updates once a day (usually overnight) and can show the status of returns for the current year plus the 3 prior years. Status is typically available starting 3 weeks after you file.
Will I Get an Additional Refund?
If your amendment results in a refund, the IRS issues it once processing is complete. The amount may differ from what you expected, since the IRS reviews and verifies all changes before issuing payment. The refund may also arrive by a different method than the one you chose on your original return.
What If I Owe Additional Tax?
Pay the balance as soon as you can to limit interest and penalties. The IRS will let you know if any balance remains after processing.
Federal vs. State Amendments
Federal: Changes are reported on Form 1040-X and, in most cases, can be e-filed. (See E-filing Amended Returns (Form 1040X) for details and restrictions.)
State: If your federal changes affect your state return, you'll likely need to amend that too. State amended returns can't be e-filed — they must be printed and mailed. (See Where Do I Mail My Amended State Return?)
Frequently Asked Questions
Does IRS acceptance mean my amendment is approved? No — acceptance just means the IRS received it for processing. They still need to review the changes before anything is finalized.
Can I file another amendment while one is processing? It's best to wait until your current amendment finishes processing before filing another.
Will amending my federal return affect my state return? It might, if the federal changes affect items reported on your state return.