After filing your tax return, you may find that you made an error or forgot to enter something on it. The IRS strongly recommends that people use the Interactive Tax Assistant's Should I File an Amended Return? questionnaire to help determine if they should correct an error or make other changes to the tax return they already filed.
Common Reasons People May Need to File an Amended Return:
Entering income incorrectly
Not claiming credits for which they're eligible
Claiming deductions incorrectly
The IRS may correct math or clerical errors on a return, and they may also accept returns without certain required forms or schedules, so in those cases there's no need for you to amend the return.
You should also wait if you are expecting a refund, because you need to allow time for your original tax return to be processed before filing an amended return. The IRS is automatically refunding money to eligible people who filed their tax return reporting unemployment compensation before changes made by the American Rescue Plan. It may take the agency more than 21 days to issue refunds for some 2020 tax returns that require review including incorrect recovery rebate credit amounts or returns that used 2019 income to figure the earned income tax credit and additional child tax credit.
Here are some things you should know if you do need to amend your tax return:
You may now use tax software to file an electronic Form 1040-X. At this time, only tax year 2019 and 2020 Forms 1040 and 1040-SR returns can be amended electronically, and only if the original 2019 or 2020 tax return was also filed electronically.
If you cannot or choose not to file your 1040-X electronically, you should complete a paper Form 1040-X.
You can mail a paper 1040-X to the IRS address listed in the form's instructions under Where to File. People filing Form 1040-X in response to an IRS notice should mail it to the IRS address that is on the notice.
You should attach copies of any forms or schedules affected by the change.
You need to file a separate Form 1040-X for each tax year. When mailing amended returns to the IRS, put each tax year in a separate envelope and enter the year of the original return being amended at the top of Form 1040-X.
You should pay additional tax owed as soon as possible to limit interest and penalty charges.
You must file Form 1040-X to claim a refund within three years from the date you timely filed your original tax return or within two years from the date you pay the tax, whichever is later.
You can track the status of an amended return three weeks after mailing it by using the Where's My Amended Return? tool on the IRS website.