There are approximately 50 treaties between the United States and other countries. A nonresident alien may claim that part or all of the payment is not subject to federal tax withholding because of treaty exemption. The visa type further identifies the primary purpose of the visit and relates to a section of law. In the majority of cases, the section of law refers to the Immigration and Nationality Act.
Nonimmigrant visas have one letter and one number or one letter.
Immigrant visas have either two letters and one number or one letter and two numbers, and the holders are classified as resident aliens. The Visa Waiver Program allows nationals of designated countries to apply for admission to the U.S. at land border ports as well as air and seaports. This status allows nonresident aliens to enter the United States for business or pleasure for up to 90 days without obtaining a visa. The compensation of a foreign visitor for services they provided to the University. Payments to nonresident aliens are subject to unique tax withholding and reporting requirements.