35 ILCS 200/16-185
The Board shall make a decision in each appeal or case appealed to it, and the decision shall be based upon equity and the weight of evidence and not upon constructive fraud, and shall be binding upon appellant and officials of government. The extension of taxes on any assessment so appealed shall not be delayed by any proceeding before the Board, and, in case the assessment is altered by the Board, any taxes extended upon the unauthorized assessment or part thereof shall be abated, or, if already paid, shall be refunded with interest as provided in Section 23-20.
The decision or order of the Property Tax Appeal Board in any such appeal, shall, within 10 days thereafter, be certified at no charge to the appellant and to the proper authorities, including the board of review or board of appeals whose decision was appealed, the county clerk who extends taxes upon the assessment in question, and the county collector who collects property taxes upon such assessment.
The final administrative decision of the Property Tax Appeal Board shall be deemed served on a party when a copy of the decision is: (1) deposited in the United States Mail, in a sealed package, with postage prepaid, addressed to that party at the address listed for that party in the pleadings; except that, if the party is represented by an attorney, the notice shall go to the attorney at the address listed in the pleadings; or (2) sent electronically to the party at the e-mail addresses provided for that party in the pleadings. The Property Tax Appeal Board shall allow each party to designate one or more individuals to receive electronic correspondence on behalf of that party and shall allow each party to change, add, or remove designees selected by that party during the course of the proceedings. Decisions and all electronic correspondence shall be directed to each individual so designated.
If the Property Tax Appeal Board renders a decision lowering the assessment of a particular parcel after the deadline for filing complaints with the board of review or board of appeals or after adjournment of the session of the board of review or board of appeals at which assessments for the subsequent year or years of the same general assessment period, as provided in Sections 9-215 through 9-225, are being considered, the taxpayer may, within 30 days after the date of written notice of the Property Tax Appeal Board's decision, appeal the assessment for such subsequent year or years directly to the Property Tax Appeal Board.
If the Property Tax Appeal Board renders a decision lowering the assessment of a particular parcel on which a residence occupied by the owner is situated, such reduced assessment, subject to equalization, shall remain in effect for the remainder of the general assessment period as provided in Sections 9-215 through 9-225, unless that parcel is subsequently sold in an arm's length transaction establishing a fair cash value for the parcel that is different from the fair cash value on which the Board's assessment is based, or unless the decision of the Property Tax Appeal Board is reversed or modified upon review.
35 ILCS 200/16-185