When Is the Deadline to Appeal Your Cook County Property Taxes?

How Cook County property tax appeal deadlines work

I get this question more than almost any other: "When can I appeal?" The honest answer is that there is no single countywide deadline. Cook County runs appeals on a township schedule, and your township opens and closes on its own dates. Miss your window and you usually wait a full year for the next one, so the timing matters as much as the argument.

There are also two separate places to appeal in the same year, each with its own deadline. The tool above pulls both for your township. Here is what each one means.

The Cook County appeal ladder

1. Cook County Assessor's OfficeYour first chance. After the Assessor sets your assessment, your township opens for roughly 30 to 45 days. This is the easiest and cheapest level to win a correction, and a strong filing here can resolve the whole thing.
2. Cook County Board of ReviewA separate, independent body that opens its own window later in the year, even if you already filed with the Assessor. You can appeal here whether or not you appealed to the Assessor, and many of my reductions come from this level.
3. PTAB or Circuit CourtIf the Board's decision still is not right, the Illinois Property Tax Appeal Board or the Circuit Court can review it. Different rules and a different clock apply here.

What a "township" has to do with your taxes

Cook County is divided into 38 townships, and the county reassesses one third of them each year on a rotating three-year cycle. Your township controls when your appeal window opens, when it closes, and which year your property was last reassessed. That is why two neighbors a few miles apart can have completely different deadlines. The lookup above resolves your exact township from the county's own parcel records, so you are not guessing.

Why the dates move every year

The Assessor publishes each township's open and close dates as the year progresses, and the Board of Review sets its own windows after that. Reassessment years, staffing, and appeals volume all shift the calendar. I keep this tool current from the county's published dates and the Board of Review's township notices, but appeal windows can still change on short notice. Always confirm the exact date with the official source linked in your results before you rely on it.

Should you wait for your deadline or start early?

Start early. The deadline is the last day to file, not the day to begin. The strongest appeals are built on evidence: comparable assessments, recent sales, photos of condition issues, or income and vacancy figures for rental and commercial property. Gathering that takes time. If you wait until the window is almost closed, you file a weaker case. If you want help, the earlier you reach out, the more we can build.

Frequently asked questions

Every Cook County township appeal deadline

Here is the full schedule for all 38 Cook County townships. The Assessor column shows the last day to file at the Assessor's Office. The Board of Review column shows that body's separate window.

Always confirm a date with the official source before relying on it: Assessor calendar and Board of Review. This tool is provided by Aaron Fox Law and is not a government website.

*This tool and the information on this page are provided for general guidance only and do not constitute legal advice or create an attorney-client relationship. Appeal deadlines are set by the Cook County Assessor and the Cook County Board of Review and can change. Always confirm your deadline with the official source before acting.