Cal. Health & Safety Code § 5474.7

The tax collector may, in his discretion, issue separate bills for such installments of fees or charges and interest. The county shall be compensated for services, if any, rendered in connection with the levy, collection and enforcement of such installments of fees or charges and interest in an amount to be fixed by agreement between the board of supervisors and the legislative body of the entity. The compensation shall not exceed 1 percent of all money collected for the entity.