Cook County assessment appeals
What happens after a Cook County Board of Review appeal?
After the Cook County Board of Review issues its written decision, a property owner may ask the Illinois Property Tax Appeal Board (PTAB) to review the assessment. The filing window is measured from the notice's postmark or personal service date.
By Check the County, operated by Embento LLC. Updated September 29, 2026. This is general public-record research information, not legal, tax or appraisal advice.
Where PTAB fits
The annual Cook County appeal sequence begins with the Assessor, followed by a separate Board of Review opportunity. Our Assessor vs Board of Review guide explains those two offices and their separate township filing windows. After the Board of Review decision, PTAB is the state quasi-judicial body that reviews property assessments.
According to the Illinois Property Tax Appeal Board FAQ, as of September 2026, PTAB's jurisdiction is limited to the correct assessment of a property. It does not review tax rates or tax bill amounts, and it does not grant exemptions.
Check the notice date and filing requirements
According to PTAB's filing instructions, as of September 2026, a petition must be filed within 30 days of the postmark date or personal service date of the Board of Review's written decision notice. PTAB charges no filing fee.
PTAB says an incomplete petition is returned. It must be corrected and resubmitted within 30 days or the appeal is dismissed. Read the current official instructions before filing.
What can support a residential appeal?
According to PTAB, as of September 2026, residential appeals may be supported with comparable properties of similar age, construction, location and square footage, or with an appraisal. Our comparable-sales guide explains how to assess potential comparisons.
For local Cook County context, browse township guides or find your township by city. Use PTAB's filing page and FAQ for current forms and procedures.