Cal. Civ. Code § 55.1-1203

A. Any landlord may require a refundable application deposit in addition to a nonrefundable application fee. If the applicant fails to rent the unit for which application was made, from the application deposit the landlord shall refund to the applicant within 20 days after the applicant's failure to rent the unit or the landlord's rejection of the application all sums in excess of the landlord's actual expenses and damages together with an itemized list of such expenses and damages. If, however, the application deposit was made by cash, certified check, cashier's check, or postal money order, such refund shall be made within 10 days of the applicant's failure to rent the unit if the failure to rent is due to the landlord's rejection of the application. If the landlord fails to comply with this section, the applicant may recover as damages suffered by him that portion of the application deposit wrongfully withheld and reasonable attorney fees.
B. A landlord may request that a prospective tenant provide information that will enable the landlord to determine whether each applicant may become a tenant. The landlord may photocopy each applicant's driver's license or other similar photo identification, containing either the applicant's social security number or control number issued by the Department of Motor Vehicles pursuant to § 46.2-342 . However, a landlord shall not photocopy a U.S. government-issued identification so long as to do so is a violation of 18 U.S.C. § 701. The landlord may require, for the purpose of determining whether each applicant is eligible to become a tenant in the landlord's dwelling unit, that each applicant provide a social security number issued by the U.S. Social Security Administration or an individual taxpayer identification number issued by the U.S. Internal Revenue Service.
C. An application fee shall not exceed $50, exclusive of any actual out-of-pocket expenses paid by the landlord to a third party performing background, credit, or other pre-occupancy checks on the applicant. However, where an application is being made for a dwelling unit that is a public housing unit or other housing unit subject to regulation by the U.S. Department of Housing and Urban Development, an application fee shall not exceed $32, exclusive of any actual out-of-pocket expenses paid to a third party by the landlord performing background, credit, or other pre-occupancy checks on the applicant.
D. A landlord shall consider evidence of an applicant's status as a victim of family abuse, as defined in § 16.1-228 , to mitigate any adverse effect of an otherwise qualified applicant's low credit score. In order to establish the applicant's status as a victim of family abuse, an applicant may submit to the landlord (i) a letter from a sexual and domestic violence program, a housing counselor certified by the U.S. Department of Housing and Urban Development, or an attorney representing the applicant; (ii) a law-enforcement incident report; or (iii) a court order. If a landlord does not comply with this section, the applicant may recover actual damages, including all amounts paid to the landlord as an application fee, application deposit, or reimbursement for any of the landlord's out-of-pocket expenses that were charged to the prospective tenant, along with attorney fees.