How To File An Amended Tax Return

It’s not uncommon to make a mistake on your federal tax return or leave out important information such as a tax deduction or credit that you’re entitled to—but the IRS has a process that gives you a second chance.

“An amended tax return is filed when a taxpayer realizes a mistake was made on the initial return and needs to correct it,” says Nell Curtis, an accounting instructor at Milwaukee Area Technical College in Wisconsin.

Here’s what you need to know about filing an amended return and how to avoid common mistakes when filing.

What You Need For Your 2021 Taxes

How to File an Amended Return

Taxpayers should use Form 1040-X, Amended U.S. Individual Income Tax Return, to file an amendment. You can check the status of your amended return three weeks after it was filed by going to the Where’s My Amended Return? online tool or by calling 866-464-2050.

You can track the status of amended returns for the current year and up to three prior years. When you check online or call, you’ll need to prove your identity by entering information, including your taxpayer identification number (this could be your Social Security number) along with your date of birth and zip code.

There are three processing stages of your return: received, adjusted and completed.

Some common reasons to file include changing the number of dependents you claim, a changed total amount of income from when you originally filed, or that you can now claim tax deductions or credits.

You can amend your return by going online for Form 1040X, Amended U.S. Individual Income Tax Return—you can correct forms 1040, 1040-A, 1040-EZ, 1040-NR, or 1040-NR EZ. The online form lets you input your data and download it for submission to the IRS.

Why You May Need to File an Amended Return

You may need to file an amended return to claim a bigger refund—or because you owe the IRS more money than you initially thought.

Some reasons people file tax return amendments to a return is because they forgot to report some income, realizing they should or shouldn’t have claimed certain credits or incorrectly claiming dependents, Curtis says.

Other common reasons for filing an amended tax return include tax forms like W-2s or 1099s arriving late after you have already filed your return. An amended return is necessary to report any income that was left off your first return, Curtis says.

Tax laws often change—tax credits and deductions are often expanded or taken away, says Daniel Fan, managing director, head of wealth planning at First Foundation Advisors, an Irvine, California-based financial institution.

For example, in 2021, the child tax credit increased up to $3,600 and included children 17 years and under.

Another example could be someone taking too much of a deduction for State and Local Income Taxes (SALT) – the deduction was limited to $10,000 starting in 2018 under the Tax Cuts and Jobs Act.

People also amend their taxes if they had a change in filing status, change in the number of claimed dependents, incorrectly claimed tax credits and deductions or incorrectly reported income, says Daniel Gibson, a partner at New York-based tax and accounting firm EisnerAmper.

If you realize you made a mistake or left out some pertinent information, such as claiming a credit or receiving a refund, you have three years from the date you originally filed your return, assuming it was filed by the original return deadline. But once you file an amended return, don’t expect a quick turnaround.

“Unfortunately, it can take anywhere from four to six months,” Gibson says.

One Big Mistake Taxpayers Make When Filing an Amended Return

The most common mistake many taxpayers make when they need to file an amended return is failing to file an amended state income tax return also, Curtis says.

“Many states rely on the federal return, so if the federal return is amended often the state return needs to be amended as well,” she says. “Additionally, when filing an amended return, the IRS is looking for documentation to support the amendment, so failing to include the appropriate documentation as to why the taxpayer is amending the return is a common mistake as well.”

You usually don’t need to file an amended return if you discover math or clerical errors on a recently filed tax return, Gibson says.

“The IRS will often correct those types of mistakes on its own,” he says.

If the IRS does not fix the math mistake, you should file an amendment to make the correction.

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