Trademark protection in the US can come from a combination of sources. The protections can be found in federal law, state law, and common law. With respect to to trademark registration, Each source has its own requirements and levels of protection, however, a federal trademark registration provides the most legal protection to a trademark. A trademark must be used in interstate commerce in order to be federally registered, or must be used across state lines.
If a trademark is used solely in one state or intrastate, then depending on the requirements of that specific state, the trademark can be registered in that state. State trademark registration can protect your trademark in that state, whereas a federal trademark registration allows a business or individual the benefit of nationwide trademark protection. Thus, to enjoy the maximum protections under the law, the best option is to be authorized to prosecute or register trademarks with the United States Patent and Trademark Office.
Common Law Trademarks
Common Law Trademarks may or may not be registrable under federal or state trademark law. However, typically, the trademark owner, whether an individual, entrepreneur or company, determines not to officially prosecute and register its trademark. Thus, under common law, the trademark owner may develop certain enforceable rights in a limited geographic area in which the trademark is used and/or advertised. However, because the trademark owner does not hold a federal or state trademark registration, it is not entitled to certain legal presumption of validity and enforceability enjoyed by registered trademark owners. Common law trademarks, which have not been prosecuted or officially registered, are often very difficult to enforce.