California Code, Revenue and Taxation Code - RTC § 6830

(a) For the purpose of identifying persons or businesses who may owe taxes or other amounts, or for the purpose of collecting taxes, interest, additions to tax, and penalties, the board may enter into agreement with one or more private persons, companies, associations, or corporations providing these services outside this state with respect to the identification of persons or businesses who may owe taxes or other amounts, or the collection of taxes, interest, additions to tax, and penalties.  The agreement may provide, at the discretion of the board, the rate of payment and the manner in which compensation for services shall be paid.  The compensation may be added to the amount required to be identified or collected by the collection agency or provider of these services from the tax debtor.  The board shall provide the necessary information for the contractor to fulfill its obligation under that agreement.

(b) With the approval of the board, the contractor may, as part of the collection process, refer the tax debt for litigation by its legal representatives in the name of the board.