The Cook County Board of Review is the second, independent place to appeal your property assessment after the Assessor, and for most homeowners it is the one that matters. For tax year 2025 the Board decided 254,531 residential appeals, counting each appeal once, and reduced 128,024 of them: 59.0% in the north suburbs, 41.3% in the south suburbs, 44.6% in the city. The Assessor, deciding first, reduced 20.7%, 12.3% and 16.8% of the same kinds of appeals.
What the Board of Review is
The Board is a separate county office with three elected commissioners, one per district. It does not set assessments; it reviews the Assessor's, township by township, on complaint from the owner. It sits at 118 N. Clark Street, Room 601, Chicago, IL 60602, (312) 603-5542, open weekdays 9 to 5, and takes appeals online at appeals.cookcountyboardofreview.com. Filing is free. A Board decision can be taken further to the Illinois Property Tax Appeal Board or the circuit court, but the Board is where nearly every residential appeal ends.
2026 Board of Review windows
The Board opens townships in groups, each for about 30 days, after the Assessor certifies them. The first two 2026 groups: Evanston, New Trier, Norwood Park, Oak Park, River Forest, Riverside and Rogers Park (August 3 – September 1), then Berwyn, Cicero, Elk Grove, Lake View, Maine and Palos (August 31 – September 29). The rest follow as the Assessor certifies each township, including Worth, Orland, Proviso, Palatine, Wheeling, Bremen, Lemont, Calumet, Stickney and Lyons; if the Assessor did not reduce your 2026 value, that is your second appeal. The deadlines page shows each township's status the day the Board posts it.
What the Board actually decided last year
County-published outcomes, tax year 2025, all residential (Class 2) appellants, counted by appeal (a condominium building's units, decided together, count once):
| Region | Board of Review: decided | Reduced | Average cut | Assessor, same year: reduced |
|---|---|---|---|---|
| North suburbs | 114,684 | 67,703 (59.0%) | 7.1% | 20.7% |
| South and west suburbs | 60,704 | 25,045 (41.3%) | 8.6% | 12.3% |
| City of Chicago | 79,143 | 35,276 (44.6%) | 8.5% | 16.8% |
The north's 59.0% reflects its 2025 reassessment: reassessment years produce more uniformity errors and the Board corrects more of them. The south and west suburbs were reassessed for 2026, so expect the same pattern there this cycle. Among south and west suburban townships last year, Cicero (51.3%) and Calumet (45.7%) were at the top and Lemont (32.0%) and Palos (35.4%) at the bottom.
How to file a Board of Review appeal
- Confirm your township is open. Appeals are only accepted during the township's window.
- Choose the argument. Lack of uniformity (your assessed value per square foot is above comparable homes in your neighborhood code) wins most residential appeals. Overvaluation (a recent purchase or appraisal below the Assessor's market value) is the second. Factual errors in the property description are a third.
- Attach evidence. Five to eight comparables with PINs, square footage and assessed values; the closing statement or appraisal for an overvaluation claim; photos for condition. Our free property check builds the comparable set from the county's data.
- File online at the Board's portal before the window closes. You do not need to have filed with the Assessor, and the Assessor's decision does not bind the Board.
- Wait for the decision. Most residential appeals are decided on the papers, without a hearing. Decisions arrive after the township closes, and a reduction flows into the second-installment bill.
Common questions
Can I appeal at the Board if I skipped the Assessor? Yes. The venues are independent. Do I need a lawyer? No. Whether representation changes the outcome depends on the evidence; the county's own data by venue is in Cook County Property Tax Attorney: When Representation Matters. Does a reduction last? A reduction in a reassessment year generally carries until the next reassessment, three years later. What does it cost? Filing is free. Our fee is 25% of the first year's savings and nothing if there is no reduction.
Start with your address and we file at the Board the day your township opens. Source for outcome figures: Cook County Board of Review and Assessor appeal files as loaded September 6, 2026.
