Cal. Code of Civil Procedure § 417.10

Proof that a summons was served on a person within this state shall be made: (a) If served under Section 415.10, 415.20, or 415.30, by the affidavit of the person making the service showing the time, place, and manner of service and facts showing that the service was made in accordance with this chapter. The affidavit shall recite or in other manner show the name of the person to whom a copy of the summons and of the complaint were delivered, and, if appropriate, the person’s title or the capacity in which the person is served, and that the notice required by Section 412.30 appeared on the copy of the summons served, if in fact it did appear. If service is made by mail pursuant to Section 415.30, proof of service shall include the acknowledgment of receipt of summons in the form provided by that section or other written acknowledgment of receipt of summons satisfactory to the court. (b) If served by publication pursuant to Section 415.50, by the affidavit of the publisher or printer, or the publisher’s or the printer’s foreperson or principal clerk, showing the time and place of publication, and an affidavit showing the time and place a copy of the summons and of the complaint were mailed to the party to be served, if in fact mailed. (c) If served pursuant to another law of this state, in the manner prescribed by that law or, if no manner is prescribed, in the manner prescribed by this section for proof of a similar manner of service. (d) By the written admission of the party. (e) If served by posting pursuant to Section 415.45, by the affidavit of the person who posted the premises, showing the time and place of posting, and an affidavit showing the time and place copies of the summons and of the complaint were mailed to the party to be served, if in fact mailed. (f) All proof of personal service shall be made on a form adopted by the Judicial Council. (g) This section shall remain in effect only until January 1, 2027, and as of that date is repealed.