31 CFR § 800.252 - U.S. business.
(a) The term U.S. business means any entity, irrespective of the nationality of the persons that control it, engaged in interstate commerce in the United States.
(b) Examples:
(1) Example 1. Corporation A is organized under the laws of a foreign state and is wholly owned and controlled by a foreign national. It engages in interstate commerce in the United States through a branch or subsidiary. Its branch or subsidiary is a U.S. business. Corporation A and its branch or subsidiary are each also a foreign person.
(2) Example 2. Corporation A is organized under the laws of a foreign state and is wholly owned and controlled by a foreign national. Corporation A does not have a branch office, subsidiary, or fixed place of business in the United States. It exports and licenses technology to an unrelated company in the United States. It also provides remote technical support services to customers that are in the United States, but does not have any assets or personnel located in the United States. Assuming no other relevant facts, Corporation A is not a U.S. business.
(3) Example 3. Corporation A, a company organized under the laws of a foreign state, is wholly owned and controlled by Corporation X. Corporation X is organized in the United States and is wholly owned and controlled by U.S. nationals. Corporation A does not have a branch office, subsidiary, or fixed place of business in the United States. It exports goods to Corporation X and to unrelated companies in the United States. Assuming no other relevant facts, Corporation A is not a U.S. business.