Cal. Ins. Code § 1600.5
An agent designated by a foreign insurer as provided in this article may file with the insurance commissioner a written statement of resignation as such agent which shall be signed and execution thereof shall be duly acknowledged by the agent. Thereupon, the authority of the agent to act in such capacity shall cease and the commissioner shall forthwith give written notice of such resignation by mail to the insurer addressed to its principal office as shown by his records. If an agent who has been appointed by a foreign corporation as provided in this article dies or resigns or removes his residence from the State of California, the insurer shall forthwith file with the commissioner an appointment of a new agent on a form provided by the commissioner for such purpose and pay the filing fee therefor, and such filing shall be deemed to revoke any prior designation of agent.
Ca. Ins. Code § 1600.5