California Code, Government Code - GOV § 965.8

Where any provision of this division requires a certificate of the Director of Finance or the Director of Transportation that a sufficient appropriation exists for the payment of a claim, settlement, compromise, or judgment or requires a certificate of the Director of Finance or the Director of Transportation that a sufficient appropriation exists to provide for an offset, a writ of mandate is an appropriate remedy to compel the Director of Finance or the Director of Transportation to so certify if a sufficient appropriation in fact exists for that purpose.