Cal. Rev. & Tax. Code § 8956

If, at the time a person ceases to be a user or vendor under this part, the board holds security pursuant to Section 8951 in the form of cash, government bonds, or insured deposits in banks or savings and loan institutions, the security when applied to the account of the taxpayer shall be deemed to be a payment on account of any liability of the taxpayer to the board on the date the person ceases to be a user or vendor under this part.