California Code, Government Code - GOV § 16530

A surety upon any bond to secure demand or time deposits may terminate the bond as to future liability by giving 10 days' written notice of termination to the Treasurer. Such notice of termination shall not affect any liability accruing prior to the expiration of the 10-day period.

Within 10 days after receipt of such a notice of termination, the Treasurer shall require other acceptable security or withdraw the deposits secured by the bond to be terminated.