To start with, I should mention that many tax preparation companies will give you any number of free consultations on tax issues — they will only charge you if you use their services to file a tax form, such as an amended return. I know that H&R Block has international tax specialists who are familiar with the issues facing F-1 students, so they might be the right people to talk about your specific situation.
According to TurboTax support, you should prepare a completely new 1040NR, then submit that with a 1040X. GWU’s tax department says you can submit late 8843, so you should probably do that if you need to claim non-resident status for tax purposes.
(Updated on Nov 8, 2019): According to the 1040X form instructions on the IRS website (pg 7):
Also, use Form 1040X if you should have filed Form 1040 (or, for years before 2018, Form 1040, 1040A, or 1040EZ) instead of Form 1040NR or 1040NR-EZ, or vice versa.
To amend Form 1040NR or 1040NR-EZ, 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 1040X.
- Don’t enter any other information on page 1. Also, don’t complete Parts I or II on page 2 of Form 1040X.
- Enter in Part III the reason why you are filing Form 1040X.
- Complete a new or corrected return (Form 1040, Form 1040NR, etc.).
- Across the top of the new or corrected return, write “Amended.”
- Attach the new or corrected return to the back of Form 1040X.
For more information, see Pub. 519, U.S. Tax Guide for Aliens.