What is the legal term for a company formed in one state but doing business in another?

The legal term for a company formed in one state but doing business in another is a foreign corporation.

“Foreign” does not necessarily mean formed in another country. In U.S. business law, it usually means incorporated under one state’s laws while operating in a different state. A corporation incorporated in Delaware but conducting substantial business in California, for example, is foreign to California.

A foreign corporation commonly must register, or “qualify,” to do business in the state where it operates. That process may require a filing, a registered agent, periodic reports, and payment of state fees or taxes. The exact threshold for “doing business” varies by state; isolated transactions may not require qualification.

The main mix-up is with “multinational corporation,” which describes a company operating across national borders, not the domestic state-to-state legal status. “Domestic corporation” means the corporation is formed in the state where it is conducting the relevant business, while “alien corporation” is an older or context-dependent term and is not the standard answer here.