Cal. Code of Civil Procedure § 701.010

(a) Except as otherwise provided by statute, when a levy is made by service of a copy of the writ of execution and a notice of levy on a third person, the third person at the time of levy or promptly thereafter shall comply with this section. (b) Unless the third person has good cause for failure or refusal to do so: (1) The third person shall deliver to the levying officer any of the property levied upon that is in the possession or under the control of the third person at the time of levy unless the third person claims the right to possession of the property. (2) To the extent that the third person does not deny an obligation levied upon, or claim a priority over the judgment creditor’s lien, the third person shall pay to the levying officer both of the following: (A) The amount of the obligation levied upon that is due and payable to the judgment debtor at the time of levy. (B) Amounts that become due and payable to the judgment debtor on the obligation levied upon during the period of the execution lien. (3) If the third person makes a delivery or payment to the levying officer pursuant to this section, the third person shall execute and deliver any documents necessary to effect the transfer of the property. (c) For the purposes of this section, “good cause” includes, but is not limited to, a showing that the third person did not know or have reason to know of the levy from all the facts and circumstances known to the third person.