California Code
ARTICLE 5 - Proof of Service
Section 417.30.

417.30. After a summons has been served on a person, proof of service of the summons as provided in Section 417.10 or 417.20 shall be filed, unless the defendant has previously made a general appearance.

(Amended by Stats. 2005, Ch. 300, Sec. 3. Effective January 1, 2006.)