Code Civ. Proc., § 706.101

(a) An earnings withholding order shall be served by the levying officer upon the employer by delivery of the order to any of the following:

(1) The managing agent or person in charge, at the time of service, of the branch or office where the employee works or the office from which the employee is paid. In the case of a state employee, the office from which the employee is paid does not include the Controller’s office unless the employee works directly for the Controller’s office.

(2) Any person to whom a copy of the summons and of the complaint may be delivered to make service on the employer under Article 4 (commencing with Section 416.10) of Chapter 4 of Title 5.

(b) Service of an earnings withholding order shall be made by personal delivery as provided in Section 415.10 or 415.20 or by delivery by first-class mail, postage prepaid. When service is made by first-class mail, service is complete at the time of receipt of the earnings withholding order, as indicated in the employer’s return, or the date of mailing if the date of receipt is not indicated on the employer’s return. If the levying officer attempts service by first-class mail under this subdivision and does not receive the employer’s return within 15 days from the date of mailing, the levying officer shall make service as provided in Article 3 (commencing with Section 415.10) of Chapter 4 of Title 5. For purposes of this section, “employer’s return” refers to the Judicial Council-issued form specified by Section 706.126.

(c) The state may issue an earnings withholding order directly, without the use of a levying officer, for purposes of collecting overpayments of unemployment compensation or disability benefits pursuant to Article 4 (commencing with Section 1375) of Chapter 5 of Part 1 of, and Article 5 (commencing with Section 2735) of Chapter 2 of Part 2 of, Division 1 of the Unemployment Insurance Code. The earnings withholding order shall be served by registered or certified mail, postage prepaid, with return receipt requested. Service is deemed complete at the time the return receipt is executed by, or on behalf of, the recipient. If the state does not receive a return receipt within 15 days from the date of deposit in the mail of the withholding order, the state shall refer the earnings withholding order to a levying officer for service in accordance with subdivision (b).

(d) Except as provided in subdivision (b) or (c), service of any notice or document under this chapter may be made by first-class mail, postage prepaid. If service is made on the employer after the employer’s return has been received by the levying officer, the service shall be made by first-class mail, postage prepaid, on the person designated in the employer’s return to receive notices and at the address indicated in the employer’s return, whether or not that address is within the county. This subdivision does not preclude service by personal delivery (1) on the employer before the employer’s return has been received by the levying officer or (2) on the person designated in the employer’s return after its receipt.

(e) Notwithstanding subdivision (b), if the judgment creditor so requests, the levying officer shall make service of the earnings withholding order by personal delivery as provided in Section 415.10 or 415.20.