California Revenue & Taxation Code
Cal. Rev. & Tax. Code § 8109
(a)
A refund filed pursuant to subdivision (b) of Section 8101 shall be paid to the claimant within 20 calendar days of the receipt of a claim for refund by the Controller.
(b)
Notwithstanding subdivision (a), the claim for refund shall be submitted on a properly completed form or in substantially similar format, as prescribed by the Controller.
Source: official text