You need to abandon your sole proprietor dba (which requires a form and publication) and file the same name dba for your LLC (which requires a form and publication.)
The above is general legal and business analysis. It is not "legal advice" but analysis, and different lawyers may analyse this matter differently, especially if there are additional facts not reflected in the question. I am not your attorney until retained by a written retainer agreement signed by both of us. I am only licensed in California. See also avvo.com terms and conditions item 9, incorporated as if it was reprinted here.
Attorney Doland has already answered your question. I write only to provide you with a link to California's fictitious business name law [visit the link below] and to strongly suggest that you speak with your own California-licensed attorney to help you with (1) the LLC formation, (2) consider what to name the company and its products or services, and (3) registering the trade name, trademarks and fictitious business name.
The above response is general information ONLY and is not legal advice, does not form an attorney-client relationship, and should NOT be relied upon to take or refrain from taking any action. I am not your attorney. You should seek the advice of competent counsel before taking any action related to your inquiry.
Attorney Doland has advised the two steps you take. There is also another two steps you should consider for additional protection and safety and you need to do that with an Intellectual Property Lawyer, preferably one licensed in Cal, such as Attorney Doland. First, have your attorney run a servicemark/trademark clearance search to be sure no one else has registered this DBA as their servicemark, either with the State of California or with the US Patent & Trademark Office. Second, if that comes up clean, get your own servicemark and/or trademark registration(s) to protect against later adopters of the same mark. This is for both your safety against infringement charges and for your protection against infringers. The greater reputation that attaches to your DBA, the more important those two additional steps become.
I am not your lawyer and you are not my client. Free advice here is without recourse and any reliance thereupon is at your sole risk. This is done without compensation as a free public service. I am licensed in IL, MO, TX and I am a Reg. Pat. Atty. so advice in any other jurisdiction is strictly general advice and should be confirmed with an attorney licensed in that jurisdiction.
My colleagues have already answered your question. As with any small forming or existing business, you would benefit from consulting an attorney to make sure that you don't miss protecting any aspect of your business that may be protectable such as patent, trademark, copyright or trade secret. In addition, you want to make sure that contracts (at least important ones) are vetted through an attorney as well. Good Luck.
Concurring with my colleagues, you will find the forms Attorney Doland referred to from the Los Angeles Registrar-Recorder/County Clerk's Office, the Office responsible for maintaining and publishing DBA records in Los Angeles County.
This content is intended for educational purposes only. Armen Kiramijyan is authorized to practice law in California. The above content is intended for California residents only. This content provides only general information which may or may not reflect current legal developments. Armen Kiramijyan expressly disclaims all liability in respect to actions taken or not taken based on any of the contents of this website. The above content DOES NOT create an attorney-client relationship. Armen Kiramijyan does not represent you unless you have expressly retained Armen Kiramijyan in person at the KAASS LAW office. KAASS LAW helps clients in: Los Angeles, Burbank, Hollywood, Glendale, Van Nuys, North Hollywood, Studio City, Highland Park, Eagle Rock, Sunland, Tujunga, Sylmar, La Crescenta, La Canada, Beverly Hills, Westwood, Santa Monica, Brentwood. Pacoima, Montebello, Commerce, Alhambra, Downey, Bell, Maywood, Walnut Park, Vernon, Lynwood, Echo Park, Silverlake, Mission Hills, Northridge, North Hills, Porter Ranch, Chatsworth, Reseda, San Diego, Chula Vista.