CORRECTED REPLY
Do you mean that you were a resident alien in 2020 but you filed Form 1040-NR instead of Form 1040, or do you mean that you filed a nonresident state tax return for a state where you were a resident?
In either case, was your resident or nonresident status the same for the entire year, or did your status change during the year?
How did you file your 2020 tax return? Did you use TurboTax?
Are you the same person who posted a similar question a few days ago with user name kanakarajumanupa, but with the resident and nonresident statuses reversed?
Thanks for your reply.
Yes, I was a resident alien in 2020 but I filed Form 1040-NR instead of Form 1040. My status was the same for the whole year. I didn't use TurboTax at the time for my 2020 tax return.
Finally, no, I'm not this person you mentioned.
In order to amend the Form 1040-NR tax return that you filed, to change to Form 1040, you have to prepare a completely new Form 1040 tax return, the way you should have filed it. You attach the new Form 1040 tax return, with all necessary schedules and forms, to a minimal Form 1040-X. Here is an excerpt from the IRS Instructions for Form 1040-X that covers your situation.
Resident and nonresident aliens. Use Form 1040-X to amend Form 1040-NR. Also use Form 1040-X if you should have filed Form 1040 instead of Form 1040-NR, or vice versa.
If you are filing Form 1040-X by paper to amend Form 1040-NR, or to file the correct return, do the following.
• Enter your name, current address, and social security number (SSN) or individual taxpayer identification number (ITIN) on the front of Form 1040-X.
• Don’t enter any other information on page 1. Also don’t complete Parts I or II on page 2 of Form 1040-X.
• Enter in Explanation of Changes (Part III) the reason you are filing Form 1040-X.
• Complete a new or corrected return (Form 1040, 1040-SR, 1040-NR, etc.).
• Across the top of the new or corrected return, write “Amended.”
• Attach the new or corrected return to the back of Form 1040-X.
You can easily complete the Form 1040-X by hand, following the IRS instructions. You can download Form 1040-X and its instructions from the following links.
You can use TurboTax to prepare the new Form 1040 tax return, but not TurboTax Online. TurboTax Online is only for the current tax year, which is now 2022. To prepare a Form 1040 for 2020 you have to use the CD/Download TurboTax software for 2020. You can purchase a download at the following link. There is no free filing for past years.
You might get a better price from a reputable online seller that still has TurboTax for 2020 in stock.
The CD/Download TurboTax software can only be used on a Windows or Mac computer, not on a mobile device or a Chromebook.
When you finish the 2020 Form 1040 tax return in TurboTax, print it and, following the IRS instructions, write "Amended" at the top of the first page, attach it to the Form 1040-X that you filled out, and file it by mail. Whenever you file by mail you should use certified mail with a return receipt, so that you get tracking and proof of delivery.