Business (Name Availability)
From Consumer Wiki
If an individual wishes to establish a business under a fictitious name, and does not want to form a corporation, the owner of the business may "file" for the fictitious name at the County Clerk Recorder's Office of the county which will serve as the principal place of business. The filing of a name does not protect a business from identical name duplication.
If a business moves from another state into California and has not established a permanent place of business with an address, that business must file in the county office of location.
To locate your local County Clerk Recorder's Office, click on the link below:
County Clerk Recorder's Office list by county