Determine the appropriate county in which to file your DBA. Generally, you must register in the county where your principal office is located. If you operate in several counties, the principal place of business is the county in which your company has its headquarters. If you are not sure where to file your DBA, contact the County Clerk's office in one of the counties in which you conduct business.
Conduct a fictitious business name search to determine whether the name that you want to use is available. The County Clerk’s office does not offer this service, so you will need to conduct your own search online or in person at the County Clerk's office before registering your fictitious name.
Complete a Fictitious Business Name Statement and file the form with the County Clerk’s office. You can obtain this form from the County Clerk’s office, and it is also available online in some counties. Be sure to comply with the filing deadlines. Your corporation must register a DBA within 40 days of commencing business under a fictitious name. Some counties let you file the statement online or by mail, but registering in person at the County Clerk’s office ensures that all paperwork is completed correctly and received in a timely manner. The County Clerk will charge a fee at the time of filing.