Buffalo, New York Independent document preparation service

Appeal Packets

Property tax appeal packets, prepared for the owner to file

Est. 2026, Buffalo, New York

A private document preparation service. Not the Cook County Assessor’s Office, not the Cook County Board of Review, not a law firm, and not legal advice.

Cook County Assessor appeals · Deadlines

Cook County property tax appeal deadlines, township by township.

Cook County does not run one appeal deadline for everyone. Each township has its own window, opened by its reassessment notice and closed by its own last file date. This page keeps the current calendar in one place, with the notice date and the last file date for each township whose window is open in this cycle.

Current cycle · South and west suburbs, 2026

The dates below are the Assessor’s published notice dates and last file dates, checked November 4, 2026.

01

How the county’s appeals work

1
One third of the county is reassessed each year. In 2026 it is the south and west suburbs. The Assessor mails each owner a Reassessment Notice with the new estimated market value, and that township’s appeal window opens on the mailing date.
2
Each township has its own last file date. The owner appeals to the Assessor through the county’s online appeal, and filing is free. Once a township’s last file date passes, its Assessor window is closed for the year.
3
The Board of Review opens a second window. After the Assessor certifies a township’s results, the Cook County Board of Review opens its own window for that township, usually about 30 days. An owner can file at the Board even if they did not appeal to the Assessor, and the same evidence works at both.
02

The current township windows

We open packets township by township, matched to each window as it opens. Rich Township is the township we serve today. The other townships are listed for information, and this page will say when packets open for each one.

Township Notice mailed Last file date Window
Proviso — November 4, 2026 Closed
Orland September 24, 2026 November 6, 2026 Open
Jefferson September 29, 2026 November 12, 2026 Open
Schaumburg October 6, 2026 November 19, 2026 Open
Thornton October 8, 2026 November 23, 2026 Open
North Chicago October 9, 2026 November 24, 2026 Open
Niles October 20, 2026 December 3, 2026 Open
Rich October 21, 2026 December 4, 2026 Open — packets available
Hanover October 22, 2026 December 7, 2026 Open
South Chicago October 30, 2026 December 15, 2026 Open
Bloom November 3, 2026 December 17, 2026 Open

Dates are from the Cook County Assessor’s published assessment calendar, checked November 4, 2026. The Assessor can adjust a date; if this page and the Assessor’s calendar ever differ, the Assessor’s date governs. The rest of the county’s townships run on the same pattern as their reassessment years come around.

03

The second window: the Board of Review

The Cook County Board of Review is a separate county office from the Assessor. After the Assessor certifies a township’s results, the Board opens its own filing window for that township, usually about 30 days, with evidence due shortly after the filing close. An owner who appealed to the Assessor can file again at the Board, and an owner who missed the Assessor window can start at the Board; the same evidence works at both offices.

The Board announces each township’s dates as it goes. For Rich Township, the Board window is expected in early 2027; the dates will be posted here when the Board publishes them.