California Code, Revenue and Taxation Code - RTC § 12428

(a) An insurer or surplus line broker against which a deficiency assessment is made under Section 12424 or 12425 may petition for redetermination of the deficiency assessment within 30 days after service upon the insurer or surplus line broker of the notice thereof, by filing with the board a written petition setting forth the grounds of objection to the deficiency assessment and the correction sought. At the time the petition is filed with the board, a copy of the petition shall be filed with the commissioner.

If a petition for redetermination is not filed within the period prescribed by this section, the deficiency assessment becomes final and due and payable at the expiration of that period.

(b) This section shall become operative on July 1, 2013.