Cal. PRC § 3920

If the coowner fails to sign and deliver the writing to the delinquent within 20 days after the contribution, the coowner so failing is liable to the delinquent for a penalty of one hundred dollars ($100) to be recovered by the delinquent in any court of competent jurisdiction. If the coowner fails to deliver the writing within 20 days after the contribution, the delinquent, with two disinterested persons having personal knowledge of the contribution, may make an affidavit setting forth in what manner, the amount of, to whom, and upon what claim, the contribution was made. The affidavit, or a record thereof in the office of the county recorder of the county in which the claim is situated, is prima facie evidence of the contribution.