Gov. Code, § 22560

(a) The board may charge or assess each public agency as defined in Section 22009.03 and each public agency shall pay and reimburse the state at the times and in the amounts as the board may determine, the approximate cost to the state, of any work, services, equipment, and other administrative costs relating to a division under Article 2.5 (commencing with Section 22150) of Chapter 1 or the referendum provided by Article 2 (commencing with Section 22300) of Chapter 2 and requested by the agency. The charges may differ from public agency to public agency.

(b) A penalty of 50 percent of the amount charged or assessed shall be added to each charge or assessment that is delinquent 90 days after a notice of the charge or assessment was mailed by the board. The total amount of the charge, assessment, and penalty that remains unpaid after 120 days shall accrue interest at the rate of 7 percent per annum. The charges, assessments, penalties, and interest collected shall be paid into the Treasury and credited as revenue to the Old Age and Survivors’ Insurance Revolving Fund for use by the board upon appropriation by the Legislature pursuant to subdivision (b) of Section 22600.