For Scholars Hub Page View: U.S. Taxes All international scholars are required to file a U.S. (federal) tax return even if you do not have U.S. source income. [1] Employment Employment information for faculty, staff, and researchers. [2] Social Security Number & ITIN All international students are required to file a U.S. (federal) tax return even if you do not have U.S. source income. [3]