Cal. Rev. & Tax. Code § 30301

At any time within three years after any amount of tax becomes due and payable, and at any time within 10 years after the last recording or filing of a notice of state tax lien under Section 7171 of the Government Code, the board may transmit notice of the delinquency to the Attorney General, who shall at once proceed by appropriate legal action to collect all sums due the state.