In the United States, the USPTO maintains a database of registered trademarks. The database is open to the public; however a licensed attorney may be required to interpret the search results. Furthermore as trademarks are governed by federal law, state law, and common law, a thorough search as to the availability of a mark is very important. In the United States, obtaining a trademark search and relying upon the results of an opinion issued by an attorney may insulate a trademark user from being required to pay treble damages and attorney’s fees in a trademark infringement case as it demonstrates that the trademark user performed due diligence and was using the mark in good faith. The USPTO internally captures more information about trademarks than what they publicly disclose on their official search website. For example, the USPTO collects information about what exactly is shown inside every logo trademark filing.
Trademarks may also be searched on third-party databases, such as LexisNexis, Dialog and Compu-Mark.
In Europe and if a community trademark has to be filed, searches have to be conducted with the OHIM (Community Trademark Office) and with the various national offices. An alternative solution is to conduct a trademark search within private databases.