California Code, Code of Civil Procedure - CCP § 2025.240

(a) The party who prepares a notice of deposition shall give the notice to every other party who has appeared in the action. The deposition notice, or the accompanying proof of service, shall list all the parties or attorneys for parties on whom it is served.

(b) If, as defined in subdivision (a) of Section 1985.3or subdivision (a) of Section 1985.6, the party giving notice of the deposition is a subpoenaing party, and the deponent is a witness commanded by a deposition subpoena to produce personal records of a consumer or employment records of an employee, the subpoenaing party shall serve on that consumer or employee all of the following:

(c) If the attendance of the deponent is to be compelled by service of a deposition subpoena under Chapter 6 (commencing with Section 2020.010), an identical copy of that subpoena shall be served with the deposition notice.