Form 1040-X vs. Form 1040: What’s the Difference?

tax preparer filing an amended return with TaxSlayer Pro

Errors on tax returns can happen, even for tax professionals. Form 1040X allows preparers like you to modify information that was incorrectly submitted on your client’s return.

If a client fails to disclose information like a W-2 or a side gig, you will need to amend their return. We’ve compiled some tips for completing a Form 1040-X, Amended U.S. Individual Income Tax Return.

When to not to file an amended return

  • If the only error was math-related, then the Internal Revenue Service (IRS) will make the correction.
  • If a specific form or schedule was forgotten, wait for the IRS to mail a request for the missing form.
  • If the IRS sends the taxpayer a letter requesting a specific form to be completed, you do not need to file an amended return. Simply fill out and submit the new form.

When to file a Form 1040-X amended return

  • If you are correcting the filing status or dependents for your client.
  • If you need to change the amount of total income due to some unexpected income or forgetting to include income from side jobs.
  • To claim (or remove) a deduction or credit not done on your client’s original return.

Completing the proper paperwork

You will be using Form 1040-X, Amended U.S. Individual Income Tax Return. Before you begin an amendment, locate and save a paper copy of both the original state and federal return. On a second paper copy of the original return, make changes in the margins, then copy those numbers to the new form. If you completed the taxpayer’s return with TaxSlayer Pro, read this article for detailed instructions on how to amend an existing or new return. If you amend a client’s federal return, you may also need to amend their state return.

Be sure to check the box at the top and have your client explain they are amending on the second page. Don’t forget to attach any additional forms or schedules to avoid delays or any penalties.

Submitting Form 1040-X

Form 1040-X can be filed electronically or printed and mailed in. Your clients have three years from the due date of the original return or two years from the date their return was paid to file an amendment. The IRS has provided an online tool to help taxpayers and preparers track the status of an amended federal return for the current year and up to three prior years. 

When to send in an amended tax return

The right time to send an amendment depends on whether your client is waiting for a refund or owes more taxes. If he or she is waiting for money, then wait until the refund is received. If money is owed, then file Form 1040-X as soon as possible. 

Checking the status of an amended return

To check the status of your client’s amended return filed with Form 1040-X, use the Where’s My Amended Return tool on the IRS website. If you or your client has not heard anything back after three weeks, the status should show on this tool. You must have the taxpayer identification number or Social Security number, their date of birth, and ZIP code to use this tool.

If you still have questions, TaxSlayer Pro is ready to help with our online support center. TaxSlayer Pro will also help you to be more accurate when filing client’s returns so that you know you’re submitting it correctly the first time.

This article was last updated on August 2, 2021. The information is up to date through tax year 2022 (taxes filed 2021).