I'm using F-1 with an OPT to work last year. I didn't know that I don't need to pay medicare and social security taxes. I submitted form 1040A (e-file) via one website. And this website doesn't provide a service for 1040NR. What should I do? Should I resubmit 1040NR? Can I cancel the 1040A that I submitted?

Thechait:

You will need to amend your return using Form 1040X. Attach the correct Form 1040NR when you amend the return, along with the Form 843 to claim the Social Security and Medicare tax refund.