Cal. Code of Civil Procedure § 415.21

(a) Notwithstanding any other law, any person shall be granted access to a gated community or a covered multifamily dwelling for a reasonable period of time for the sole purpose of performing lawful service of process or service of a subpoena upon displaying a current driver’s license or other identification, and one of the following: (1) A badge or other confirmation that the individual is acting in the individual’s capacity as a representative of a county sheriff or marshal, or as an investigator employed by an office of the Attorney General, a county counsel, a city attorney, a district attorney, or a public defender. (2) Evidence of current registration as a process server pursuant to Chapter 16 (commencing with Section 22350) of Division 8 of the Business and Professions Code or of licensure as a private investigator pursuant to Chapter 11.3 (commencing with Section 7512) of Division 3 of the Business and Professions Code. (b) This section shall only apply to a gated community or a covered multifamily dwelling that is staffed at the time service of process is attempted by a guard or other security personnel assigned to control access to the community or dwelling. (c) For purposes of this section, “covered multifamily dwelling” means either of the following: (1) An apartment building, including a timeshare apartment building not considered a place of public accommodation or transient lodging, with three or more dwelling units. (2) A condominium, including a timeshare condominium not considered a place of public accommodation or transient lodging, with four or more dwelling units.