Where and when can I file an appeal?

You can file a Cook County property tax appeal online during your township’s official filing window.

Appeals are filed at one of two levels:

1. Cook County Assessor’s Office

2. Cook County Board of Review

Each level has its own filing period, and deadlines are strict.

Where Do I File an Appeal?

1. Cook County Assessor’s Office

Most property owners start here.

You can file online through the Cook County Assessor’s appeal portal during your township’s open appeal period.

This is the first opportunity to challenge your assessed value.

Both homeowners and commercial property owners can submit:

• Comparable sales

• Property condition evidence

• Income and expense statements for commercial properties

2. Cook County Board of Review

If you disagree with the Assessor’s decision, or you did not file with the Assessor, you may appeal to the Board of Review. You can file when the appeal window opens for your township.

The Board of Review is a separate agency and provides another opportunity to reduce your assessment.

When Can I File an Appeal?

There is no single countywide deadline.

Appeal windows are based on:

• Your township

• The assessment cycle

• The specific agency handling the appeal

Each township typically has a filing period of about 30 days.

You must file before the posted deadline. Late appeals are not accepted.

How to Check Your Township’s Filing Window

Cook County property owners should verify their township’s current appeal deadline before filing.

You can check active and upcoming deadlines here:

Cook County Property Tax Appeal Deadlines page..

This page provides updated filing periods for:

• Residential properties

• Commercial properties

• Township-specific deadlines

Important Timing Information

Cook County follows a three-year reassessment cycle:

• One year for Chicago

• One year for North Suburbs

• One year for South and West Suburbs

You can appeal:

• During your reassessment year at the Assessor

• Again, when the Board of Review opens for your township

Commercial property owners should prepare early because income documentation may be required.

Key Takeaways

• You file a Cook County property tax appeal online.

• Appeals are filed with the Assessor or the Board of Review.

• Deadlines are township-specific.

• Filing windows usually last about 30 days.

• There are no extensions for missed deadlines.

If you own a home or business property in Cook County, check your township’s deadline early. This helps protect your right to appeal and may lower your property tax bill.