You only need to file if you have income that is subject to tax, such as wages, tips, scholarships that exceed tuition and required fees, dividends, etc. The tax return you must file is Form 1040NR, the Federal Tax Return for Nonresidents. If you have any earned income, your tax return is due by April 15; otherwise the filing deadline is June 15. If you owe more tax than was withheld, you must pay it by the appropriate date. If more tax than you owe has been withheld, you should file a return to claim a refund for the excess amount that was withheld.