Trademarks may be filed at either the state or federal level. State trademarks protect your mark in a specific state while federal trademarks normally protect your mark in all the states. State trademarks generally provide far less legal protection than federal trademarks. Businesses operating in only one state should trademark in that state. However, businesses operating in interstate commerce may file for a federal trademark. Obviously, a business intent on expanding nationally or internationally should conduct a trademark search and file a federal trademark as soon as possible.