RTC §12251: (a) Each calendar year, insurers transacting insurance in this state and whose annual tax for the preceding calendar year was twenty thousand dollars ($20,000) or more shall make prepayments of the an

(a) Each calendar year, insurers transacting insurance in this state and whose annual tax for the preceding calendar year was twenty thousand dollars ($20,000) or more shall make prepayments of the annual tax for the current calendar year imposed by Section 28 of Article XIII of the California Constitution and this part, provided that prepayments shall not be made with respect to the tax on ocean marine insurance underwriting profit or any retaliatory tax. (b) This section shall become operative on July 1, 2013.