Cal. Rev. & Tax. Code § 6933

Within 90 days after the mailing of the notice of the board’s action upon a claim filed pursuant to Article 1 (commencing with Section 6901), the claimant may bring an action against the board on the grounds set forth in the claim in a court of competent jurisdiction in any city or city and county of this state in which the Attorney General has an office for the recovery of the whole or any part of the amount with respect to which the claim has been disallowed.

Failure to bring action within the time specified constitutes a waiver of any demand against the state on account of alleged overpayments.