California Code, Government Code - GOV § 12424

The Controller may render service pertinent to financial, budgetary and taxation problems and procedures for any county, city, city and county, any other political subdivision, or any district of the State upon such terms and conditions as may be agreed upon between the Controller and the governing body of such county, city, city and county, other political subdivision or district.  The money received for such service shall be paid into the State Treasury to the credit and in augmentation of the current appropriation for the support of the State Controller, or, as the case may be, that division of the Controller's Office furnishing the service.