No. Registering a trademark is optional, not mandatory. In the United States, a trademark arises from use, not registration, so it is possible to own a valid trademark without registering it. Until a trademark is registered, it is called a “common law ” trademark. A common law trademark may be enforced in court without registering it first. The geographic scope of a common law trademark, however, is limited to the geographic area of trade. Thus, the exclusive right to use a common law trademark that functions as a source identifier in only one state is limited to that state. Federally registered trademarks have nationwide protection.