Cal. Corp. Code § 2317

When any corporate agent for service of process has been designated prior to the effective date and such designation of agent included a name of a city, town or village wherein the corporate agent maintained an office, service on such agent may be effected at any office of the agent set forth in the certificate of the corporate agent filed pursuant to Section 1505 of the new law or filed pursuant to Section 3301.5, 3301.6, 6403.5 or 6403.6 of the prior law, whether or not such office is in said city, town or village.