Cal. Civ. Proc. Code § 1987

(a) Except as provided in Sections 68097.1 to 68097.8, inclusive, of the Government Code, the service of a subpoena is made by delivering a copy, or a ticket containing its substance, to the witness personally, giving or offering to the witness at the same time, if demanded by him or her, the fees to which he or she is entitled for travel to and from the place designated, and one day’s attendance there. The service shall be made so as to allow the witness a reasonable time for preparation and travel to the place of attendance. The service may be made by any person. If service is to be made on a minor, service shall be made on the minor’s parent, guardian, conservator, or similar fiduciary, or if one of those persons cannot be located with reasonable diligence, service shall be made on any person having the care or control of the minor or with whom the minor resides or by whom the minor is employed, and on the minor if the minor is 12 years of age or older. If the minor is alleged to come within the description of Section 300, 601, or 602 of the Welfare and Institutions Code and the minor is not in the custody of a parent or guardian, regardless of the age of the minor, service also shall be made upon the designated agent for service of process at the county child welfare department or the probation department under whose jurisdiction the minor has been placed.
(b) In the case of the production of a party to the record of any civil action or proceeding or of a person for whose immediate benefit an action or proceeding is prosecuted or defended or of anyone who is an officer, director, or managing agent of any such party or person, the service of a subpoena upon any such witness is not required if written notice requesting the witness to attend before a court, or at a trial of an issue therein, with the time and place thereof, is served upon the attorney of that party or person. The notice shall be served at least 10 days before the time required for attendance unless the court prescribes a shorter time. If entitled thereto, the witness, upon demand, shall be paid witness fees and mileage before being required to testify. The giving of the notice shall have the same effect as service of a subpoena on the witness, and the parties shall have those rights and the court may make those orders, including the imposition of sanctions, as in the case of a subpoena for attendance before the court.
(c) If the notice specified in subdivision (b) is served at least 20 days before the time required for attendance, or within any shorter period of time as the court may order, it may include a request that the party or person bring with him or her books, documents, electronically stored information, or other things. The notice shall state the exact materials or things desired and that the party or person has them in his or her possession or under his or her control. Within five days thereafter, or any other time period as the court may allow, the party or person of whom the request is made may serve written objections to the request or any part thereof, with a statement of grounds. Thereafter, upon noticed motion of the requesting party, accompanied by a showing of good cause and of materiality of the items to the issues, the court may order production of items to which objection was made, unless the objecting party or person establishes good cause for nonproduction or production under limitations or conditions. The procedure of this subdivision is alternative to the procedure provided by Sections 1985 and 1987.5 in the cases herein provided for, and no subpoena duces tecum shall be required.
Subject to this subdivision, the notice provided in this subdivision shall have the same effect as is provided in subdivision (b) as to a notice for attendance of that party or person.