35 ILCS 200/8-40
The circuit court for the county in which a property assessed, or some part of such property, is situated may review all final administrative decisions of the Department in administering this Code. The Administrative Review Law and the rules adopted under it apply to and govern all proceedings for the judicial review of final administrative decisions of the Department under Section 8-35. The term "administrative decision" is defined as in Section 3-101 of the Code of Civil Procedure, and includes assessment ratios and percentages for equalization of assessments determined by the Department under Sections 17-5 through 17-30. Any review of assessment ratios and percentages for equalization of assessments under the Administrative Review Law shall not delay the computation, mailing or payment of tax bills. If a final court decision holding the Department's ratios or percentages in error comes after the mailing of the tax bills, an adjustment shall be made on all bills in the assessment district in the first tax billing following the decision to credit taxpayers with any payments which may have exceeded the maximum tax rate in rate-limited levies of non-home rule taxing units. Service upon the Director or the Assistant Director of the Department of summons issued in an action to review a final administrative decision of the Department shall be service upon the Department.
Appeals from all final orders and judgments entered by the circuit court upon review of the Department's determination in any case shall be taken as in other civil cases.
35 ILCS 200/8-40