The documents you would generally need to complete your Sprintax Calculus application would be:
1. Passport and US Visa (if applicable);
2. History of your previous US immigration statuses; You can find such here: https://i94.cbp.dhs.gov/
3. Valid taxpayer ID - SSN/ITIN (if any);
4. Form DS-2019 Certificate of Eligibility for Exchange Visitor (J-1) Status (applicable to J visa holders);
5. Form I-20 Certificate of Eligibility for Nonimmigrant Student Status (applicable to F and M visa holders);