55 ILCS 5/6-31008
The expenses of conducting the audit and making the required audit report or financial statement for each county, whether ordered by the county board or the Comptroller, shall be paid by the county and the county board shall make provisions for such payment. If the audit is made by an auditor or auditors retained by the Comptroller, the county, through the county board, shall pay to the Comptroller reasonable compensation and expenses to reimburse him for the cost of making such audit. Moneys paid to the Comptroller pursuant to the preceding sentence shall be deposited into the Comptroller's Audit Expense Revolving Fund.
Such expenses shall be paid from the general corporate fund of the county.
Contracts for the performance of audits required by this Division may be entered into without competitive bidding.
55 ILCS 5/6-31008