Cook County, Illinois · Chicago
Cook County property tax appeal guide
Chicago's county, and the only Illinois county that classifies: residential property is assessed at 10% of market value rather than the statewide 33⅓%. Complaints are filed township by township on the dates in each township's notice, so there is no single Cook deadline. You appeal through the Cook County Assessor / Cook County Board of Review; Illinois uses A written complaint to your County Board of Review (Illinois has no statewide form) filed with the County Board of Review.
Cook County appeal deadline
No single statewide date, Cook County runs township by township; other counties are 30 days after the assessment list is published.
Illinois has no single statewide deadline. In Cook County, complaints are filed township by township on the dates printed in the township's reassessment notices (35 ILCS 200/16-115), so your window depends on where you live and reopens each reassessment cycle. In every other county, the deadline is on or before 30 calendar days after your township's assessment list is published (35 ILCS 200/16-55). Check your county Board of Review's calendar for your township's dates.
How to appeal in Cook County
1. Watch for your township's reassessment notice
In Cook County, townships are reassessed on a rolling three-year cycle and each mails its own notice; your filing window runs from that notice (35 ILCS 200/16-115). Outside Cook, watch for your township's assessment list to be published.
2. File a complaint with the Board of Review
Cook County: file by your township's deadline. Every other county: file on or before 30 calendar days after the assessment list is published (35 ILCS 200/16-55). There is no filing fee. Note that the statute calls this a complaint, not an appeal, at this stage.
3. Build your evidence
Two arguments work. Overvaluation: recent sales of similar homes show your market value is too high, which you prove by a preponderance of the evidence. Lack of uniformity: comparable properties are assessed lower per square foot than yours, which under Kankakee County Board of Review v. Property Tax Appeal Board, 131 Ill. 2d 1 (1989), requires clear and convincing evidence.
4. Board of Review decision
The Board of Review reviews your complaint and may correct your assessment (35 ILCS 200/16-95 in Cook). It issues a written decision.
5. PTAB or Circuit Court (optional)
If you disagree, you may appeal to the state Property Tax Appeal Board within 30 days of the board's written decision (35 ILCS 200/16-160). Alternatively, you may pay under protest and file a tax objection in Circuit Court after exhausting the Board of Review (35 ILCS 200/23-5, 23-10).
Cook County property tax FAQ
What is the property tax appeal deadline in Cook County, Illinois?
No single statewide date, Cook County runs township by township; other counties are 30 days after the assessment list is published. Illinois has no single statewide deadline. In Cook County, complaints are filed township by township on the dates printed in the township's reassessment notices (35 ILCS 200/16-115), so your window depends on where you live and reopens each reassessment cycle. In every other county, the deadline is on or before 30 calendar days after your township's assessment list is published (35 ILCS 200/16-55). Check your county Board of Review's calendar for your township's dates.
What form do I use to appeal in Cook County?
Illinois uses A written complaint to your County Board of Review (Illinois has no statewide form), filed with the County Board of Review. There is no filing fee to appeal.
What is the property tax appeal deadline in Illinois?
There is no single statewide date. Cook County files township by township on the dates printed in each township's reassessment notice (35 ILCS 200/16-115). Every other county runs 30 calendar days from publication of the assessment list (35 ILCS 200/16-55). Check your County Board of Review's calendar.
Other Illinois counties
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