State DBA Laws
DBA laws differ from state to state, but most states require some form of registration before you can use a DBA. Registration is made at a government office, either at the state, county or city level. A government database of records for DBA registrations should be available for public viewing at these offices. A list of the registration requirements for each state is available on the U.S. Small Business Administration website.
State Level Registration
States that require DBA registration at the state level of government typically require registration with the same state office that oversees the registration of corporations and trademarks. These state offices will have a database of registered names that can be searched via telephone or mail inquiry to the office, with some having online access to the database. For example, Florida requires DBA registration with the Division of Corporations of the Florida Department of State, which includes on its website a search engine for its database of registered DBA names.
Local Level Registration
DBA registration at the local government level is done either at a county, city or town office. For example, county DBA registration typically occurs at the county clerk's office, such as in California, or at the county courthouse, such as in Georgia. Registration is typically required only in the county where the business is principally located. The county clerk's records can be checked for active DBA filings. In Massachusetts, the law requires DBA registration in every city or town clerk's office where the business is operating under an assumed name. Therefore, in any locality where the business is operating under an assumed name, the city or town clerk's records can be checked for a DBA.
Miscellaneous State Registration Laws
A few states -- Kansas, Mississippi and New Mexico -- do not require a DBA to be registered, nor do they have a procedure for registering a DBA, and so no government database of DBA names is available in these states. Arizona does not require DBA registration, but does have an optional registration procedure with the Secretary of State's office with a database of registered names that can be searched online. A search of this database, however, will not disclose those DBAs in use that are not registered.