Cal. Gov. Code § 50052
Upon or prior to publication, a party of interest may file a claim with the treasurer which must include the claimant's name, address, amount of claim, the grounds on which the claim is founded, and any other information that may be required by the treasurer. The claim shall be filed before the date the unclaimed money becomes the property of the local agency as provided under Section 50051 and the treasurer shall accept or reject that claim. If the claim is rejected by the treasurer, the party who submitted the claim may file a verified complaint seeking to recover all, or a designated part, of the money in a court of competent jurisdiction within the county in which the notice is published, and serves a copy of the complaint and the summons issued thereon upon the treasurer. The copy of the complaint and summons shall be served within 30 days of receiving notice that the claim was rejected. The treasurer shall withhold the release of the portion of unclaimed money for which a court action has been filed as provided in this section until a decision is rendered by the court.
Ca. Gov. Code § 50052