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 or Board of Review. A successful appeal can reduce your assessment and lower your 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. Each township has its own appeal window—typically you have 30 days from when your township's new assessments are published to file. Deadlines vary by township and year. OverTaxed IL helps you track your township's deadline and reminds you before it closes.

DIY ($69/property): We generate a comp packet (comparable sales and evidence) so you can file the appeal yourself at the Cook County Assessor portal for free. Full automation (Starter, Growth, Portfolio): We monitor your assessments, alert you to increases, prepare appeals and comps, and guide you through filing. PIN monitoring and deadline notifications are included in full automation; they are not included in DIY.

Today, the Cook County Assessor has not released a public e-filing API, so we cannot submit appeals on your behalf. We prepare the packet (comps, summary, PDF) and give you clear instructions to file at cookcountyassessor.com/file-appeal. Once Cook County releases an API, we will add filing-on-behalf for Starter and above.

For a strong appeal, Cook County typically expects at least 3 comparable sales (recent sales of similar properties). Our comp packet includes comparable sales from Cook County Open Data and optionally enriches with Realie (when you have a paid plan) for better coverage. Note: Board of Review Rule 15 refers to document submission requirements, not comp counts—the comparable-sales guidance above comes from Cook County Assessor requirements.

Board of Review (BOR) Rule 15 governs what documents to file with your appeal (e.g., copies of Assessor submissions, brief, other evidence). It does not specify how many comps you need. The 'at least 3 comparable sales' guidance comes from Cook County Assessor requirements. For class 2 residential (typical single-family homes), BOR Rule 15 exempts you from the brief and Historical Summary Form.

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 (typically within a few months). If approved, your assessment is reduced and your next tax bill reflects the lower value. OverTaxed IL monitors assessment changes and will notify you when we detect a reduction. You can also check status at the Cook County portal. If denied, you can appeal again in a future year or to the Board of Review.

The county assessor or board of review decides appeals. Denials can happen for many reasons. OverTaxed IL does not guarantee a reduction—county decisions are final. We focus on building strong, evidence-backed appeals to improve your odds. You can always appeal again in a future year if your assessment changes.

We offer a 30-day satisfaction guarantee for subscription plans. Contact us at support@overtaxed-il.com within 30 days of your initial signup to request a refund. See our Terms of Service for full details.

Cook County has a notification system for reassessment notices. You can sign up for alerts when your township is reassessed by visiting the Cook County Assessment & Appeal Calendar at cookcountyassessor.com/assessment-calendar-and-deadlines. OverTaxed IL also monitors your properties and sends township-open and deadline reminders when you have an active subscription.