How to Amend a Federal Tax Return

What we’ll cover:

• Generally, you have up to 3 years to file an amended tax return if you need to go back and claim a refund
• Use Form 1040X to amend a return: A separate form is needed for each tax year you’re amending
• It can take up to 16 weeks for the IRS to process an amended return

Doing your taxes isn’t a walk in the park. US federal tax law is complicated, so it’s understandable that mistakes happen. 

But did you know that you can make changes to a tax return even after it has been filed? Generally, if you need to go back and claim a credit or refund, you have up to three years from the original filing date to make any necessary corrections by submitting an amended tax return.

Now if it’s a simple mistake with your additions and subtractions, you probably won’t need to file an amended return. The IRS usually corrects minor mathematical and clerical errors for you. But let’s say you’ve overlooked a deduction or credit that you qualify for in last year’s return. You can file an amended tax return to make the correction.

Other common reasons to file an amended tax return include any changes or corrections to your filing status, income, credits, deductions, or number of dependents (yikes, did you forget a kid?). 

Steps to filing an amended tax return

If you need to file an amended tax return, do so only after you have filed your original return. 

When you’re ready to file, check the IRS website for the most up-to-date set of instructions. That said, here’s an overview of the key steps to filing an amended return. 

Step 1: Fill out IRS Form 1040X

Use Form 1040X, Amended US Individual Income Tax Return, to amend a federal tax return. This is important: You need to fill out and file a separate Form 1040X for each tax year you’re amending. Make sure to enter the year of the original return you’re amending at the top of Form 1040X.

Form 1040X provides the IRS a summary or overview of your corrections for a given tax year. This form essentially becomes your new tax return for that year. In the form, you have to provide an explanation of why you are filing an amended return and detail the changes you’re making. 

Step 2: Assemble your amended tax return

Once you have everything filled out, double check your work. Next, it’s time to put together your return, which includes your Form 1040X along with any corrected forms, schedules and supporting documents that you need to submit to justify the changes/corrections you’re making. It’s worth reiterating that missing documentations can cause delays in processing your amended tax return. 

Unless you are specifically required to do so, you do not need to include your original return. 

Step 3: Mail in your amended tax return

You cannot file Form 1040X electronically. Form 1040X, along with any corrected forms or schedules and supporting documents, must be mailed to the IRS. Yes, we mean the old-school way: envelopes, stamps, the works.

If you’re amending more than one tax return, you have to mail each Form 1040X in a separate envelope. The IRS provides a list of mailing addresses based on where you live. 

Checking the status of your amended tax return

You can track the status of your Form 1040X in about three weeks after you mailed it. The IRS provides two ways to check on your amended return:

• Use the Where’s My Amended Return (WMAR) online tool
• Call 1-866-464-2050

Whichever method you use, you need to provide your taxpayer identification number, date of birth and ZIP code to verify your identity. 

It can take up to 16 weeks for the IRS to process your amended return. If you’re expecting a refund, the IRS will send it to you after approving your amended return.