All international students in F-1 (and J-1) status are required to file at least one tax form if present in the US at any time in the previous calendar year—even if they had no US income. This process happens between January and April each year for the previous year. For example, 2013 taxes will be filed by mid-April of 2014. Students with U.S. income do pay taxes (taken out of their paycheck) and need to file taxes by April 15. Students without income (no tax has been paid) need to file by 15.