California Code, Code of Civil Procedure - CCP § 684.110

(b) If the legal process is required to be personally served under this title and service on an attorney is required under Article 1 (commencing with Section 684.010), service shall be made on the attorney in the manner provided in Section 684.040.

(c) If the legal process is required to be personally served on (1) a financial institution in connection with a deposit account or with property held for safekeeping, as collateral for an obligation owed to the financial institution or in a safe-deposit box, (2) a title insurer (as defined in Section 12340.4 of the Insurance Code) or underwritten title company (as defined in Section 12340.5 of the Insurance Code), or (3) an industrial loan company (as defined in Section 18003 of the Financial Code), service shall be made at the office or branch that has actual possession of the property levied upon or at which a deposit account levied upon is carried and shall be made upon the officer, manager, or other person in charge of the office or branch at the time of service.For purposes of this section, the office or branch at which a deposit account levied upon is carried shall mean the branch, office, or other location where the financial institution maintains the account.

(d) Notwithstanding subdivision (c), with respect to legal process served on a financial institution, if the financial institution has designated a central location for service of legal process pursuant to Section 684.115, unless the financial institution elects to treat legal process served at a branch or office as effective, that legal process so served on the branch or office will not reach those accounts or property and need not be reported on the financial institution's garnishee memorandum.

(e) Notwithstanding subdivision (c), a financial institution, title insurer, or industrial loan company, in its discretion and without violating any obligation to its customer, may act upon service of legal process at any of its offices or branches, whether or not the office or branch is the location wherein accounts or property that may be reached by the process is or are maintained or located.