How to Appeal Your Property Taxes in Cook County

A plain-language walkthrough of the Cook County appeal — both free stages, what evidence wins, and how to file it yourself as the property owner, keeping every dollar you save.

How do I appeal my Cook County property taxes?

You appeal in up to two free stages: first to the Cook County Assessor during your township’s open window, then, if needed, to the Cook County Board of Review. You file as the owner, attach comparable properties or recent sales as evidence, and submit online. Neither body charges to file.

Step 1: Confirm your township’s window

Cook County has no single county-wide deadline. The Assessor opens and closes each of the 38 townships on a rolling schedule, and the filing deadline is a hard date printed on your Reassessment Notice. Find your township’s current window first — every township hub page on this site shows it, and links to the Assessor to confirm.

Step 2: Check whether you are over-assessed

An appeal succeeds when your assessment is too high relative to comparable properties (lack of uniformity) or above your home’s market value. Look up your address to see your assessment against similar nearby homes before you file — a well-supported appeal beats a hopeful one.

Step 3: Gather your evidence

For a uniformity appeal you need comparable properties assessed lower per square foot than yours; for a market-value appeal you need recent arms-length sales below your assessed market value. Photographs of any condition problems (deferred maintenance, damage) strengthen a condition appeal.

Step 4: File with the Cook County Assessor

File online through the Assessor’s free SmartFile portal during your township’s open window. There is no charge to file, and you file as the property owner. Attach your comparable properties or sales and a short statement of why the assessment is excessive.

Step 5: If needed, file again with the Board of Review

The Board of Review is a separate, second stage that opens township-by-township after the Assessor certifies. You can appeal there even if the Assessor denied you or reduced you only partially — it is a fresh review, also free to file.

Step 6: Review the decision

Each body issues a written decision after its window closes. A reduction lowers the assessed value used to compute next year’s tax bill; you keep 100% of the resulting savings. If both stages deny you, you may appeal to the Illinois Property Tax Appeal Board or the Circuit Court.

Check your address — freeSee your own assessment math before you file. You keep 100%.

Do you need a lawyer? If you own your home individually, no — most residential appeals are self-filed. If the property is owned by an LLC, corporation, or trust, the Board of Review generally requires a licensed attorney. Details →

Find your township deadline

Your filing window depends on your township. See all Cook County township deadlines →