How to file an amended tax return

Young man sitting at desk in front of laptop, frustrated that he doesn't know how to file an amended tax return.Image: Young man sitting at desk in front of laptop, frustrated that he doesn't know how to file an amended tax return.

In a Nutshell

Whether you discovered that you made a significant mistake on your federal income tax return or received late information that you need to add, you can fix it by filing an amended tax return. Here’s how and when to file Form 1040-X.
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This article was fact-checked by our editors and Christina Taylor, MBA, senior manager of tax operations for Credit Karma. It has been updated for the 2019 and 2020 tax years.

Did you make a mistake on your federal income tax return but didn’t catch it until after you filed?

Maybe an important tax document arrived in the mail days after you e-filed your return. Don’t worry, you’re probably not in trouble. You can likely file an amended tax return to correct the error.

Filing an amended tax return gives you the chance to correct tax forms you’ve already filed, even if the mistake or omission is on an old return. Here’s what you need to know about how to file an amended tax return.

How can I file an amended tax return?

If you need to make changes to a previously filed tax return, you’ll use Form 1040-X. The form allows you to correct errors on these IRS Forms.

  • 1040: This is the main individual income tax return for federal income taxes, starting with the 2018 tax year.
  • 1040-SR: Seniors age 65 or older can use this form instead of the 1040, though both the 1040 and 1040-SR use the same schedules and instructions.
  • 1040A and 1040EZ: The IRS retired both these forms with the 2018 tax year, but if you’re filing an amendment for 2017 or earlier, you might have used one of these as your original return.
  • 1040NR or 1040NR EZ: These forms are for nonresident aliens who work in the U.S.

What information goes on a 1040-X?

Since the purpose of the 1040-X is to correct a previously filed 1040, a lot of the information requested on the two federal forms is the same.

For example, at the top of the 1040-X, you’ll check a box to tell the IRS what calendar year’s (or other year’s) return you’re amending. You’ll also provide or change your name (and your spouse’s if you’re amending a jointly filed return), address and Social Security number. Take note that you can’t amend multiple years on a single 1040-X. You must file a different 1040-X for each year you want to amend.

The form also gives you a chance to change your filing status if needed — but if you filed your original tax return as married filing jointly, you can’t switch to married filing separately.

 The most current version of the form includes three columns to complete.

  • Column A provides space for amounts from your original return or a prior amended return.
  • Column B is the difference between Column A and Column C and shows the net increase or decrease for each line you change.
  • Column C is where you input corrected information.

On the back of the form, there’s a section where you should explain why you’re filing the form. And if other schedules or forms change, you’ll include those with your 1040-X form when you submit it to the IRS, along with any new forms you received after you originally filed (like W-2s or 1099s).

Once you’re done filling out your 1040-X, you can print and mail it. You can find mailing addresses for amended returns in the instructions for the 1040-X. You’ll need to choose the address that applies to your tax situation.

The IRS also began accepting electronically filed 1040-X forms in summer 2020. Electronic filing will allow faster receipt and fewer errors on amended returns, the IRS says. For now, amendments to forms 1040 and 1040-SR can be filed electronically only for the 2019 tax year.

When do I need to file an amended tax return?

If you’ve discovered an error on tax forms submitted to the IRS, your first step is to figure out whether the mistake is one the IRS will correct for you or if you need to act.

“The purpose of an amended return is to correct an error on the original return, or to include additional information not previously reported,” says Cindy Hockenberry, director of Tax Research and Government Relations at the National Association of Tax Professionals, in Appleton, Wisconsin.

This doesn’t mean you need to notify the IRS of every little error or omission. If you simply forgot a form or made a basic math error, the IRS will either correct it for you or send out a request for missing info.

But you do need to notify the IRS right away if the error or new information affects your tax liability. Examples of mistakes that should prompt you to submit an amended federal return include any of the following:

  • Submitting taxes with the incorrect filing status
  • Misreporting your income
  • Listing the wrong number of dependents
  • Forgetting to claim tax credits or deductions

You may also need to file an amended return if you receive revised information after submitting your taxes.

“For those who receive 1099s from investment accounts, I recommend waiting at least a couple of weeks after the tax filing season opens to see if your brokerage company issues corrected 1099s,” advises ReKeithen Miller, a certified financial planner and enrolled agent with Palisades Hudson Financial Group in Atlanta. “Mutual fund companies may reclassify income reported to brokerage companies, which can change the tax treatment of the information.”

When should I submit my amended tax return?

If your amended forms will result in a larger refund, the IRS recommends waiting to submit the 1040-X until you’ve received the refund from your original return. But if you’ll owe taxes based on your amended return, send in your 1040-X and pay the taxes as soon as possible to limit penalties and interest due on late tax payments.

“Generally, you have three years from the date the return was originally filed to file an amendment,” says Micah Fraim, a CPA in Roanoke, Virginia.

But multiple factors can influence how long you have to amend a return, including when you filed the original return, when you paid any tax you owed for that year and even if you have a disability that interferes with your ability to manage your own finances. You’ll find more information in the “When To File” and “Special Situations” section of the 1040-X instructions each year. So if you think you may have missed the deadline, be sure to check if there are any special dispensations for your situation.

What happens after I file my amended tax return?

Once you‘ve submitted your amended return, you may face a long wait. Amended returns can take up to 16 weeks to process, the IRS says.

And if your return is from prior years, you likely won’t hear anything for the full duration.

This delay may seem excessive, but there’s a reason it takes so long.

“Amended returns are typically reviewed by an IRS employee, especially if a refund is due to the taxpayer,” Miller says. “Due to the labor-intensive nature of this process and the low staffing levels at the IRS, it can take a long time for the IRS to process an amended return.”

Are there any penalties for filing an amended tax return?

“There are no penalties for amending a return, but there can be penalties if there are amounts due on the amended return,” says Professor Dewey Martin, CPA and the director of the School of Accounting at Husson University in Bangor, Maine. If you owe, there may be late payment penalties and interest on the outstanding amount.

Calculating payment penalties can be tricky.

“If a balance is owed, then the penalties vary based on how much is owed and how much time has passed since the return was originally filed,” Fraim says. “For minor cases, the IRS may simply charge interest and a ‘failure to pay’ penalty. For larger mistakes, they might also impose an accuracy-related penalty.”

Plus, interest on unpaid taxes will begin accruing from the date the taxes were due, even if you had an extension of time to file.

There is some good news, though, if your amended return results in a bigger tax refund.

“While there can be interest you owe the IRS on an unpaid balance, there can also be interest earned and paid to you if you’re entitled to a refund,” Martin says.

How can I track an amended tax return?

The good news is, if you’re eager to see where your return is, there are ways to track it. You can call the IRS at 1-866-464-2050 or use its Where’s My Amended Return tool.

The tool can provide the status of amended returns for the current tax year and up to three years prior. The system can tell you if the IRS received your amended return, if your return has been adjusted to account for a refund, balance due or no change, and if the IRS is finished processing your amendment.

Once your amended return appears in the system, you can check its status daily since the system updates every day, usually at night.

Bottom line

Now that you know how to file an amended tax return and why you should do it, you can take action. If you’re going to owe money after amending your return, acting quickly, before the tax due date, could help reduce any penalties or interest. And if Uncle Sam will owe you, filing your amended return promptly could put that money in your pocket as soon as possible.

Relevant sources: IRS: Tips for Taxpayers Who Have to Amend a Tax Return (IRS Tax Tip 2018-63)IRS: Topic No. 308 Amended Returns | IRS: About Form 1040X, Amended U.S. Individual Income Tax Return | | IRS: Important Facts about Filing Late and Paying Penalties | IRS: Understanding Your CP2000 Notice | IRS: Where’s My Amended Return? | Form 1040-X (Rev. January 2020), Amended U.S. Individual Income Tax Return | IRS News: Here are five facts about the new Form 1040 | 2019 Instructions for Form 1040-NR | IRS News: Taxpayers will soon be able to file amended tax returns electronically | IRS Form 1040X, Amended U.S. Individual Income Tax Return, Frequently Asked Questions

Christina Taylor is senior manager of tax operations for Credit Karma. She has more than a dozen years of experience in tax, accounting and business operations. Christina founded her own accounting consultancy and managed it for more than six years. She co-developed an online DIY tax-preparation product, serving as chief operating officer for seven years. She is an Enrolled Agent, the current treasurer of the National Association of Computerized Tax Processors and holds a bachelor’s in business administration/accounting from Baker College and an MBA from Meredith College. You can find her on LinkedIn.

About the author: Christy Rakoczy Bieber is a full-time personal finance and legal writer. She is a graduate of UCLA School of Law and the University of Rochester. Christy was previously a college teacher with experience writing textbo… Read more.