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An amended tax return corrects mistakes on a federal tax return. Here's how to file a Form 1040-X with the IRS, when to amend a tax return and other rules you need to know.
What is an amended tax return?
IRS Form 1040-X, also known as an amended tax return, is a form that taxpayers can file with the IRS to correct mistakes made on a federal tax return. The form is typically used to reconcile errors concerning filing status, income, deductions or credits claimed or tax liability.
How does an amended tax return work?
IRS Form 1040-X is the form you fill out to amend or correct a tax return. On that form, you show the IRS your changes to your tax return and the correct tax amount.
If you’re fixing more than one year of returns, you’ll need to fill out a separate Form 1040-X for each. You’ll also need to include forms or schedules affected by the changes.
If you're filing Form 1040-X to get money back, you generally need to do so within three years of filing your original return or within two years of paying the tax, whichever is later.
You might catch an error before the IRS does, or you might receive new tax documents after you’ve already filed — if your employer sends you a revised W-2, for example. In those cases, don’t fire off a letter to the IRS saying, “Forgot to include some income. Here’s 10 bucks" or "You owe me $50." Fill out Form 1040-X.
The IRS also has an interview-style tool that can help you to determine whether your situation requires filing an amended return.
In 2020, the IRS began allowing taxpayers to file Form 1040-X electronically. This means you can file an amended 1040 and 1040-SR form for tax years 2019, 2020, 2021 (and beyond) online. If you need to file an amended return for an older return (2018 or earlier), the amended return must be filed with the IRS by mail.
You can file an amended tax return on your own
People with simple tax situations and small changes might be able to file an amended tax return on their own. Many major tax software packages include modules that will file an amended tax return. Many tax preparers are happy to file amended returns as well.
And note: Amending your federal tax return could mean having to amend your state tax return, too.
Ask if your preparer charges for an amended tax return
If you used a human tax preparer, don’t assume they will amend your tax return for free or pay the extra taxes, interest or penalties from a mistake. For example, if you forgot to give the preparer information or gave incorrect information, you’ll likely have to pay for the extra work.
If the error is the preparer’s fault, who pays for an amended tax return may depend on the wording in your client agreement.
Keep an eye on the calendar
Generally, the IRS audits only returns from the previous three tax years — though there are major exceptions. So although it might be tempting to wait and see if the IRS will catch you in an error, it might be cheaper to fess up sooner rather than later.
The IRS charges interest and penalties on outstanding tax liabilities going all the way back to the original due date of the tax payment. So the longer you wait to fix a mistake, the more expensive that mistake can get.
Where's my amended return?
It can take three weeks for an amended return to show up in the IRS’s system and more than 20 weeks to process an amended return.
If nothing has happened after 20 weeks, check the online tracking tool, call the IRS or ask someone at a local IRS office to research your amended return.
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