Cook County property tax appeals
Cook County Assessor appeal vs Board of Review appeal: what's the difference?
Cook County homeowners have two separate opportunities to ask for a review of the same property assessment: one with the Cook County Assessor and another with the Cook County Board of Review.
By Check the County, operated by Embento LLC. Updated September 19, 2026. This is general public-record research information, not legal, tax or appraisal advice.
Two offices, two filing windows
The Assessor and Board of Review are separate offices. Each opens its own filing window for each township every year. Filing with one office does not file an appeal with the other, so always confirm both the office and the township before submitting anything.
The Assessor stage comes first in the annual sequence. The Board of Review is a separate, later opportunity. A homeowner can use the Board of Review process after missing the Assessor stage or after receiving an Assessor result that did not resolve the concern.
Both offices let property owners file without a county filing fee.
What evidence belongs in either appeal?
The evidence is broadly similar at both offices. Start by confirming the county record's property facts, including property type, building size, age and other characteristics. Then look for comparable sales that genuinely resemble the property.
A low sale price by itself is not enough to make a useful comparison. Our comparable-sales guide explains how assessment neighborhood, property type, size, age, lot and sale recency affect the comparison.
How to choose the right next step
First identify your township, then check which office is accepting appeals for it. Browse the township appeal guides for local window status, and use the county's official pages to verify the current filing instructions before acting.
For a broader overview of the research process, read our Cook County property tax appeal research guide.