California Code, Vehicle Code - VEH § 40200.6

(a) If a contract is entered into pursuant to Section 40200.5, for the purposes of this article, “processing agency” means the contracting party responsible for the processing of the notices of parking violations and notices of delinquent parking violations.

(b) The governing body of the issuing agency shall establish written policies and procedures pursuant to which the contracting party shall provide services.

(c) The issuing agency shall be responsible for all actions taken by contracting parties and shall exercise effective oversight over the parties. “Effective oversight” includes, at a minimum, an annual review of the services of the processing agency and a review of complaints made by motorists using the services of the processing agency. The issuing agency shall establish procedures to investigate and resolve complaints by motorists about any processing agency.

(d) Subdivision (c) does not apply to an issuing agency that is a law enforcement agency if the issuing agency does not also act as the processing agency.