California Family Code
(a) Except as provided in subdivision (b) or in Article 3 (commencing with Section 4565), every order or judgment to pay child support may also require the payment by the child support obligor of up to one year's child support or such lesser amount as is equal to the child support amount due to be paid by the child support obligor between the time of the date of the order and the date when the support obligation will be terminated by operation of law. This amount shall be known as the "child support security deposit."
(b) Unless expressly waived by the child support obligee, the court may order the establishment of a child support trust account pursuant to this chapter in every proceeding in which a child support obligation is imposed by order of the court. Among other reasons, the court may decline to establish a child support trust account upon its finding that an adequately funded child support trust account already exists pursuant to this chapter for the benefit of the child or children involved in the proceeding or that the child support obligor has provided adequate alternative security which is equivalent to the child support security deposit otherwise required by this chapter.
If a child support security deposit is ordered, the court shall order that the moneys be deposited by the child support obligor in an interest-bearing account with a state or federally chartered commercial bank, a trust company authorized to transact trust business in this state, or a savings and loan association, or in shares of a federally insured credit union doing business in this state and having a trust department, subject to withdrawal only upon authorization of the court. The moneys so deposited shall be used exclusively to guarantee the monthly payment of child support.
The court shall also order that evidence of the deposit shall be provided by the child support obligor in the form specified by the court, which shall be served upon the child support obligee and filed with the court within a reasonable time specified by the court, not to exceed 30 days.
An account established pursuant to this chapter shall be dissolved and any remaining funds in the account shall be returned to the support obligor, with any interest earned thereon, upon the full payment and cessation of the child support obligation as provided by court order or operation of law.