
HOW APPEALS WORK IN COOK COUNTY
Your Appeal Pathway, Step by Step
There are several ways to challenge a Cook County property tax assessment. The Assessor stage is optional. After a final Board of Review decision a taxpayer may proceed to the Property Tax Appeal Board (PTAB) or, in the alternative, file a tax objection complaint in the Circuit Court of Cook County. The two post-Board remedies are alternatives, not sequential.
File the initial appeal with the Cook County Assessor while your township's appeal window is open. The Assessor sets the closing date for each township; the window opens when reassessment notices are mailed.
WINDOW: OPENS AT NOTICE MAILING; CLOSES ON THE TOWNSHIP'S LAST FILING DATE SET BY THE ASSESSOR.
Authority: Cook County Assessor's Office
If the Assessor denies relief, or if the taxpayer prefers to skip the Assessor, file with the Board of Review during its session for that township. The Board is a quasi-judicial body that reviews the Assessor's valuation based on the evidence the taxpayer submits.
WINDOW: OPENS WHEN THE BOARD'S SESSION FOR THE TOWNSHIP OPENS; CLOSES ON THE TOWNSHIP-SPECIFIC FINAL FILING DATE.
Authority: 35 ILCS 200/16-95 et seq.
After a final Board of Review decision, the taxpayer may file a state-level appeal with PTAB. PTAB conducts a de novo review based on the evidence presented.
FILING WINDOW: 30 DAYS FROM THE POSTMARK OF THE BOARD'S FINAL DECISION.
Authority: 35 ILCS 200/16-160
As an alternative to PTAB, the taxpayer may file a tax objection complaint in the Circuit Court of Cook County after the second installment of taxes is paid under protest. PTAB and the Circuit Court routes are alternative remedies; a taxpayer may not pursue both for the same year.
FILING WINDOW: WITHIN THE TIME PERIOD SET BY STATUTE AFTER THE SECOND INSTALLMENT DUE DATE.
Authority: 35 ILCS 200/23-5 through 23-25
Quick rule of thumb: Stage 1 is optional. Stage 2 is the prerequisite for Stage 3. At Stage 3 the taxpayer chooses PTAB or the Circuit Court tax objection complaint, not both.
QUESTIONS & ANSWERS
Cook County Appeal Deadline FAQ
RESOURCES
Everything You Need to File on Time
See when each cook county township is reassessed in the rotating three-year cycle so you can plan years ahead. .
The forms, comparable sales data, and supporting evidence commonly used at each appeal stage.
Plain-English description of the firm’s contingency fee structure; subject to a written engagement agreement.
Sign up for email or SMS reminders so you never miss your township's filing window.
Time-sensitive
Missing your appeal window can mean overpaying property taxes for years.
The firm's team will evaluate your property and recommend a strategy.
17
MAY 2026
Precision. Persistence. Professionalism.