Cal. Rev. & Tax. Code § 19331

If the Franchise Tax Board fails to mail notice of action on any refund claim within six months after the claim is filed, the taxpayer may prior to mailing of notice of action on the refund claim consider the claim disallowed and appeal to the board. For substitution of the 120-day period for the six-month period contained in this section in a Title 11 case, see Section 505(a)(2) of Title 11 of the United States Code.