Interstate commerce of a mark occurs when the trademark applicant or owner uses the mark on goods or in connection with the sale of goods or services that are sold or otherwise transported across state lines. The kind of use required to create or maintain a trademark under the Trademark Act must be a "bona fide use of a mark in the ordinary course of trade and not made merely to reserve a right in a mark." 15 U.S.C. §1127. Using a mark in interstate commerce is required whether applying for a trademark under an actual use application, filing a statement of use under an intent-to-use application, or filing a renewal application.

Typically, the trademark applicant engages in interstate commerce by using the mark on goods that are sold and transported across state lines, or by selling or advertising to sell services to customers from other states or countries.