Constitution of the State of Illinois Art. VII, § 9. Salaries and Fees

(a) Compensation of officers and employees and the office expenses of units of local government shall not be paid from fees collected. Fees may be collected as provided by law and by ordinance and shall be deposited upon receipt with the treasurer of the unit. Fees shall not be based upon funds disbursed or collected, nor upon the levy or extension of taxes.

(b) An increase or decrease in the salary of an elected officer of any unit of local government shall not take effect during the term for which that officer is elected.