California Code, Business and Professions Code - BPC § 8621

A complaint of any person against a nonlicensee, licensee, or registered company shall be filed with the board no later than two years after the act or omission alleged as the ground for disciplinary action or, in a matter involving fraud, gross negligence, or misrepresentation, no later than four years after commission of the act or omission. The board shall file any accusation no later than 18 months after the complaint has been filed with the board, except that with respect to a violation of Section 8637, the accusation may be filed no later than two years after the discovery by the board of the alleged facts constituting the fraud or misrepresentation prohibited by the section.