Loading
Tap on the profile icon to edit
your financial details.

All About IRS Form 1040X

Did you make a mistake on your income tax return? Don’t sweat it – it happens. Whether you forgot about a tax deduction or credit or you need to include additional sources of income, you can fix those errors by filing an amended tax return. You’ll do this by completing IRS Form 1040X. Here’s our guide to understanding and filling out that tax form.

Check out our federal income tax calculator.

What Is IRS Form 1040X?

IRS Form 1040X is the Amended U.S. Individual Income Tax Return form. It’s what taxpayers use when they need to make changes to a personal income tax return they’ve already filed. Specifically, you can use it to make corrections to IRS Forms 1040, 1040EZ, 1040A, 1040NR and 1040NR-EZ.

If you need to make adjustments to your tax return, you don’t have to completely start over. Within Form 1040X, you’ll only have to update the numbers and details that need to be changed. Once you file it, Form 1040X becomes your new tax return.

Estimate your federal income tax return with our free tax return calculator.

Deadlines for Filing Form 1040X

All About IRS Form 1040X

Taxpayers have up to three years to file an amended tax return (or up to two years after paying any taxes they owe). If you file your taxes early – like in February or March – you’ll have up to three years after the April filing deadline to submit Form 1040X. But if you file for an extension, your deadline will be three years from the date you file your tax return.

Deadlines for filing an amended tax return might change under certain circumstances. For example, the IRS might give you more time to file Form 1040X if you have a physical or mental disability.

How to Fill out Form 1040X

All About IRS Form 1040x

You’ll need to pull out a copy of your original tax return when you’re ready to fill out your amended return. You can make changes in the margins of your old tax return before completing Form 1040X. It might also be helpful to have access to the instructions for the form. You can find that online.

In order to change some of the information you included on your original tax return, you may need to have additional documents in front of you. For instance, you may need your W-2 form if you’re changing your adjusted gross income or you want to know how much federal income tax was withheld from your paychecks.

You might also need to attach other forms to Form 1040X. For example, maybe you originally took the standard deduction but you want to try and reduce your tax liability by itemizing your deductions. Since you’re itemizing, you’ll need to submit a copy of Schedule A along with your amended tax return.

It’s a good idea to take your time while you’re filling out Form 1040X. That way you won’t make any additional mistakes. And don’t forget to double-check that you’ve claimed all the deductions and tax credits that you qualify for.

Final Word

Not everyone’s tax situation is the same. If you need help completing your amended tax return, you can always reach out to a tax professional. You can also contact the IRS directly. If you need to chat with someone from the IRS face to face, you can visit a local taxpayer assistance center.

Expecting a tax refund? The IRS usually reviews amendments to tax returns within eight to 12 weeks. So your refund should arrive at some point after that.

Photo credit: ©iStock.com/alfexe, ©iStock.com/Kenishirotie, ©iStock.com/DragonImages

Jennifer Stinnett Jennifer Stinnett writes about a variety of personal finance topics for SmartAsset. Her expertise includes retirement, taxes and home buying. Jennifer has a degree from Florida State University in English with a focus on Editing, Writing and Media.
Was this content helpful?
Thanks for your input!

About Our Taxes Expert

Have a question? Ask our Taxes expert.