Cal. Civ. Code § ATCP 134.05

ATCP 134.05 Earnest money deposits and credit check fees.
(1) Accepting an earnest money deposit. A landlord may not accept an earnest money deposit or security deposit from a rental applicant until the landlord identifies to the applicant the dwelling unit or units for which that applicant is being considered for tenancy.
(2) Refunding or crediting an earnest money deposit.
(a) A landlord who receives an earnest money deposit from a rental applicant shall send the full deposit to the applicant by first-class mail, or shall deliver the full deposit to the applicant, by the end of the next business day after any of the following occurs:
1. The landlord rejects the rental application or refuses to enter into a rental agreement with the applicant.
2. The applicant withdraws the rental application before the landlord accepts that application.
3. The landlord fails to approve the rental application by the end of the third business day after the landlord accepts the applicant’s earnest money deposit, or by a later date to which the tenant agrees in writing. The later date may not be more than 21 calendar days after the landlord accepts the earnest money deposit.
(b) A landlord who receives an earnest money deposit from a rental applicant shall do one of the following if the landlord enters into a rental agreement with that applicant:
1. Apply the earnest money deposit as rent or as a security deposit.
2. Return the earnest money deposit to the tenant.
(c) A person giving an earnest money deposit to a landlord does not waive his or her right to the full refund or credit owed under par. (a) or (b) merely by accepting a partial payment or credit of that amount.
(3) Withholding an earnest money deposit.
(a) A landlord may withhold from a properly accepted earnest money deposit if the prospective tenant fails to enter into a rental agreement after being approved for tenancy, unless the landlord has significantly altered the rental terms previously disclosed to the tenant.
(b) A landlord may withhold from an earnest money deposit, under par. (a), an amount sufficient to compensate the landlord for actual costs and damages incurred because of the prospective tenant’s failure to enter into a rental agreement. The landlord may not withhold for lost rents unless the landlord has made a reasonable effort to mitigate those losses, as provided under s. 704.29, Stats.
(4) Credit check fee.
(a) Except as provided under par. (b), a landlord may require a prospective tenant to pay the landlord’s actual cost, up to the amount specified in s. 704.085 (1) (a), Stats., to obtain a consumer credit report on the prospective tenant from a consumer reporting agency that compiles and maintains files on consumers on a nationwide basis. The landlord shall notify the prospective tenant of the charge before requesting the consumer credit report, and shall provide the prospective tenant with a copy of the report.
(b) A landlord may not require a prospective tenant to pay for a consumer credit report under par. (a) if, before the landlord requests a consumer credit report, the prospective tenant provides the landlord with a consumer credit report, from a consumer credit reporting agency that compiles and maintains files on consumers on a nationwide basis that is less than 30 days old.