Cal. Code of Civil Procedure § 708.520

(a) When an application is made pursuant to Section 708.510 or thereafter, the judgment creditor may apply to the court for an order restraining the judgment debtor from assigning or otherwise disposing of the right to payment that is sought to be assigned. The application shall be made on noticed motion if the court so directs or a court rule so requires. Otherwise, it may be made ex parte. (b) The court may issue an order pursuant to this section upon a showing of need for the order. The court, in its discretion, may require the judgment creditor to provide an undertaking. (c) The court may modify or vacate the order at any time with or without a hearing on such terms as are just. (d) The order shall be personally served upon the judgment debtor and shall contain a notice to the judgment debtor that failure to comply with the order may subject the judgment debtor to being held in contempt of court.