http://www.dca.ca.gov/publications/landlordbook/looking.shtm...
> “The application fee cannot legally be more than the landlord’s actual out-of-pocket costs, and, in 2012, can never be more than $44.51. The landlord must give you a receipt that itemizes his or her out-of-pocket expenses in obtaining and processing the information about you. The landlord must return any unused portion of the fee (for example, if the landlord does not check your references).”