d.b.a.
d.b.a.
prep. short for "doing business as," when a person or entity uses a business name instead of his/her/its own. All states have requirements for filing a certificate of "doing business under a fictitious name" either with the county clerk, the state Secretary of State or some other official to inform the public as to the real person or entity behind a business name. It is not necessary if the business includes the name of the true owner and is not to be confused with the use of a corporation name, since that is registered with the state.