Generally, a non-resident alien individual is engaged in trade or business within the US if he or she:

• You are considered to be engaged in a trade or business in the United States if you are temporarily present in the United States as a nonimmigrant on an “F,” “J,” “M,” or “Q” visa. The taxable part of any U.S. source scholarship or fellowship grant received by a nonimmigrant in “F,” “J,” “M,”

 » Read more about: What is Income Effectively Connected with a US Trade or Business (ECI)?  »

US source income typically includes compensation for services, interest, dividends, rents and royalties from US sources. Basic US sourcing rules are as follows:

Type of Income:
US Source if:

Salaries, wages, other compensation
Services are performed in the US

Business income:
Personal Services
Sale of inventory – purchased
Sale of inventory – produced

Services are performed in the US
Sale takes place in US
Production allocated to US

Dividends
The payer corporation is formed in the US

Interest
The payer of the interest is a resident of the US

Rent
The rented property is located in the US

Royalties –  » Read more about: What is US Source Income?  »