Frequently asked questions

A property tax appeal is a formal request to lower your property's assessed value. In Illinois, your property taxes are based on the assessed value set by the county assessor. If you believe your assessment is too high compared to similar properties, you can file an appeal with the Cook County Assessor. Decisions are made by the county, and a change in assessed value does not produce an equal change in a tax bill.

A PIN (Property Identification Number) is a unique 14-digit number assigned to each property by the county assessor. In Cook County, you can find your PIN on your property tax bill or by searching the Cook County Assessor website. We use your PIN to look up your property, pull assessment data, and generate comparable sales for your appeal.

Cook County uses a township-based calendar, and each township has its own appeal window. We publish each township's status exactly as the county publishes it, with the source we read and the time we retrieved it, on the deadlines page. Confirm your filing deadline with the county before you file.

OverTaxed IL analyzes public Cook County records and prepares a defined Assessor-stage appeal packet. You review it, sign it, and file it yourself. The $69 packet is a preparation service. We prepare it; you review it, sign it, and file it with the county yourself.

For a residential assessment appeal, comparable assessments are usually more informative than raw sales alone: you are looking for similar nearby properties assessed lower than yours. Our packet is built from public-record comparable properties for an Assessor-stage appeal and explains what each piece of evidence is doing.

Board of Review Rule 15 governs what documents the Board requires with an appeal filed there — for example copies of Assessor submissions, briefs, and supporting evidence. It is a Board rule, published by the Board, and it applies to filings made at that stage rather than at the Assessor.

After you submit at the Cook County Assessor portal, you'll receive a Filing ID and Docket Number by email — keep them for your records. The Assessor reviews your appeal and issues a decision. You can check status at the Cook County portal.

The Cook County Assessor decides appeals, and denials happen for many reasons. OverTaxed IL is not a law firm and does not provide legal or tax advice. We do not guarantee a reduction. County decisions are final, and a change in assessed value does not produce an equal change in a tax bill. You can appeal again in a future year if your assessment changes.

If your filing is rejected or denied solely because of an OverTaxed IL procedural error in the materials we prepared, contact support@overtaxed-il.com within 30 days of the notice so we can review the issue under our Terms of Service. This does not cover county denials on the merits.

OverTaxed IL is not a law firm and does not provide legal or tax advice. We do not guarantee a reduction. County decisions are final, and a change in assessed value does not produce an equal change in a tax bill. We organize public Cook County records into an Assessor-stage appeal packet. For legal advice, consult a licensed Illinois attorney.

Not today. If your association manages multiple PINs and wants to be told when bulk support exists, use the HOA section on the homepage or email support@overtaxed-il.com. OverTaxed IL is not a law firm and does not provide legal representation.