So I am an international student on F1 in California since Sep. 2018, and did a paid internship in New York in Summer 2019. Several questions:
- For federal tax return, do I just sum the income (and withheld tax) from the two states and report in form 1040-NR?
- For state tax return, do I fill the appropriate forms for both states (i.e. 540 and IT-203)?
- Do I have to report my NY income in my California tax return? (Or vice versa)
- Is there anything I should do to avoid double taxation? Any forms other than the ones I mentioned that I have to fill?