Cook County property tax appeal deadlines: how the calendar really works

Every year, Cook County homeowners get two chances to appeal their property tax assessment: first at the Cook County Assessor's office, then at the Cook County Board of Review. Miss both, and you wait until next year.

Why deadlines depend on your township

Cook County is divided into 38 townships, and each one opens and closes on its own schedule. The Assessor works through townships one at a time, and the Board of Review follows later with its own township windows. Your deadline is not your neighbor's deadline unless you live in the same township.

The two windows that matter

• Assessor window: your first and often best chance. Filing here is free and online.
• Board of Review window: a second, independent review if you miss the Assessor or disagree with their decision.
• PTAB: the state-level option in Springfield, usually used after the Board of Review.

How to find your exact dates

We track the official township calendars so you don't have to dig through county PDFs. Check our deadlines page, pick your township, and you'll see whether your window is open, upcoming, or closed — plus the official filing links.

The smartest first step

Before any deadline matters, you need to know whether your home is actually over-assessed. Run our free 30-second check: we compare your home's assessed value per square foot against similar homes in your neighborhood using public county records. If the numbers say you're in line, you've saved yourself hours. If they say you're high, you'll know before the window opens.

NeighborComp is a private company and is not affiliated with the Cook County Assessor, Board of Review, or any government office. We do not provide legal advice and do not file appeals on your behalf.