What is an amended tax return?

An amended tax return allows you fix mistakes on a federal income tax return that you’ve already filed. There is no penalty for admitting that you made a mistake on your return, but you will have to pay late fees and interest if you owe money to the Internal Revenue Service (IRS).

You should only amend your return if there is a major mistake, like an incorrect filing status or incorrect income. For example, you should send an amended return if you forgot to include income from a 1099-MISC. You may also want to send an amended return if you forgot to claim a tax credit or deduction.

You do not need to amend your return just for math errors because the IRS usually fixes them. It also isn’t necessary just because you forgot to attach a form or schedule. If the IRS needs the missing form, it will send you a letter asking you to mail the document.

An amended return allows you to make changes to your adjusted gross income, your above-the-line deductions (like the student loan interest deduction), the standard deduction, and itemized deductions. For tax years before 2018, you can also edit your personal exemptions.

Who needs to file an amended tax return

You should file an amended return when there is a major mistake with the information you provided on your return. There are only a handful of situations when you should file an amended tax return:

• Personal information, like your Social Security number, was incorrect
• You used the wrong filing status
• You claimed the wrong number of dependents
• The income you reported is incorrect
• You forgot to include tax deductions or credits

Technically, no taxpayer needs to make an amendment to an incorrect return; it isn’t actually required. The IRS will simply notify you if you are owed a larger refund or it will charge interest on any tax bill that you owe.

Who doesn’t need to file an amended return

Don’t send an amended return for a mathematical mistake. The IRS will normally find math errors and fix them without you needing to do anything.

You also don’t need to amend your return for missing documents, such as a missing schedule. If the IRS needs that form in order to process your return, it will a letter asking you to mail the missing documents. Sending an amended return may just overcomplicate the process for the IRS.

The IRS only accepts amended returns for the past three years of tax returns. For example, the last day for most people to amend their 2018 federal tax return is April 15, 2020. That’s three years from the deadline to file 2018 returns (unless you filed a tax extension).

When to file an amended return

If you expect to receive a tax refund from your original return, the IRS suggests that you wait until you receive your original refund before sending the amended return. In the case that your amended return will result in a lower refund than what you already got, it doesn’t matter whether you use the original refund, just make sure you have enough to pay back the difference between what the IRS sent you and what you should actually have gotten.

If the information on your amended return will leave you with a tax bill, you should send your amended return and pay your bill as soon as you can. The longer you put off payment, the more you will owe. Late fees and interest start accruing the day after your tax-filing deadline.

Calculating late fees for a tax return isn’t always easy. Consider finding a tax preparer or accountant to help you get it right.

How to file an amended tax return

You can file an amended federal tax return with Form 1040X, Amended U.S. Individual Income Tax Return. You use the same form whether you originally filed Form 1040, 1040A, 1040EZ, 1040NR, or 1040NR-EZ. You also use 1040X if you previously filed the incorrect form, like if you filed a 1040NR but should have used a standard 1040.

Since you cannot electronically file an amended return, you will need to print and mail a physical copy to the proper IRS office. You can find the correct office to send the return in the table below and at the end of the instructions for Form 1040X.

(If filing your tax return stresses you out, try our guide to filing your taxes.)

IRS office mailing address for Form 1040X

Before you send in your return, make sure to double-check that the year at the top is for the correct tax year. Also recheck all the information you entered, so that you don’t have to send another amended return.

If you are sending amended returns for multiple years, mail each return in its own envelope. Make sure you include any additional forms or documents that need to accompany your return.

Form 1040X part by part

Form 1040X looks similar to a standard tax return. The top of the form is for personal information like your name, SSN, and address. Make sure to put the correct filing status. You also need to check the box next to the year of the return that you’re amending.

Then there are three parts to the form. Part I of Form 1040X has three columns where you enter information:

• Column A is where you write the amounts on your original return (on the tax return that you’re correcting).
• Column B is for the difference between what you originally reported and the corrected amounts. This shows how much you’re changing the amounts on your return.
• Column C is for you to write the corrected amount.

Part II is just for contributions to the Presidential Election Campaign Fund, which goes toward the public financing of primary and general elections. You can only give money if you didn’t contribute on your original return.

Form 1040X’s Part III is a box where you can write a description of the changes you’re making. Explain why you’re amending your tax return and then don’t forget to attach any necessary tax forms, schedules, or other documents.

At the bottom of the form, you need to write your signature, the date, and your occupation. If you’re working with a tax preparer, they will also sign and date.

Check the status of your amended return

After mailing your amended return, it may take up to three weeks just for the IRS to receive it. Once the IRS has your return, processing can take up to 16 weeks.

You can check the status of your amended return with the Where's My Amended Return? tool from the IRS.

To check your amended return status, you need to enter your zip code, date of birth, and either your Social Security number or your individual tax ID number (ITIN).