Cal. Rev. & Tax. Code § 12253

(a)Each insurer required to make prepayments shall remit them on or before each of the dates of April 1, June 1, September 1, and December 1 of the current calendar year. Remittances for prepayments shall be made payable to the Controller and shall be delivered to the office of the commissioner, accompanied by a prepayment form prescribed by the commissioner.

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