50 ILCS 310/9
The expenses of the audit and investigation of public accounts provided for by this Act, whether ordered by the governing body or the Comptroller, shall be paid by the governmental unit for which the audit is made. Payment shall be ordered by the governing body out of the funds of the unit and such authorities shall make provision for payment. Contracts for the performance of audits required by this Act may be entered into without competitive bidding. If the audit is made by a licensed public accountant retained by the Comptroller, the governmental unit shall pay to the Comptroller actual compensation and expenses to reimburse him for the cost of making such audit.
The governing body of any governmental unit having taxing powers may levy an auditing tax in an amount that will not require extension of such tax at a rate in excess of .005% of the value of all taxable property in the unit as equalized or assessed by the Department of Revenue. This auditing tax may be in excess of or in addition to any statutory limitation of rate or amount. Money received from the auditing tax shall be held in a special fund and used only for the payment of auditing expenses.
50 ILCS 310/9