IRS Tax Tip 2020-145, October 29, 2020 If taxpayers discover a mistake on their tax return, this is not necessarily cause for concern. Most errors can be fixed by filing a Form 1040-X, Amended U.S. Individual Income Tax Return. Here are some 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 may accept returns without certain required forms or schedules. In these instances, there's no need for taxpayers to amend the return. Taxpayers who do need to amend their tax return might have questions about how to do so. Here are some things they should know: Taxpayers may now use tax software to file an electronic Form 1040-X. At this time, only tax year 2019 Forms 1040 and 1040-SR returns can be amended electronically if the original 2019 tax return was also filed electronically. Taxpayers who cannot or chose not to file their 1040-X electronically should complete a paper Form 1040-X. If filing a paper 1040-X, mail it to the IRS address listed in the form's instructions PDF under Where to File. Taxpayers filing Form 1040-X in response to an IRS notice should mail it to the IRS address indicated on the notice. Attach copies of any forms or schedules affected by the change. File a separate Form 1040-X for each tax year. When mailing amended returns to the IRS, place each tax year in a separate envelope and enter the year of the original return being amended at the top of Form 1040-X. Wait – if expecting a refund – for the original tax return to be processed before filing an amended return. Pay additional tax owed as soon as possible to limit interest and penalty charges. Taxpayers should file Form 1040-X to claim a refund within three years from the date they timely filed their original tax return or within two years from the date they pay the tax, whichever is later. Track the status of an amended return three weeks after mailing using the Where's My Amended Return? tool. More Information: Interactive Tax Assistant: Should I File an Amended Return? Topic No. 308 - Amended Returns Form 1040-X Frequently Asked Questions Subscribe to IRS Tax Tips