Property Tax

Cook County property tax affects every homeowner, landlord, and investor in the county, but the system can feel confusing until you know where to look and who does what. This guide walks through how Cook County property tax is calculated, how to look up your bill, how to pay, how to get exemptions and refunds, what to do if you think your assessment is wrong, and where to get official help directly from county offices.

Make sense of your Cook County property tax bill

Before you dive into payments or appeals, it helps to understand the basic players in the Cook County property tax system and how they fit together.

In Cook County, different elected offices share responsibility for your property tax bill:

Cook County Assessor’s Office
Values your property and maintains the characteristics used to calculate your assessed value (square footage, building type, classification, etc.). The Assessor also administers homeowner-related exemptions.

Cook County Board of Review
Hears appeals from property owners who believe their assessment from the Assessor is too high or otherwise incorrect.

Cook County Clerk’s Office
Calculates tax rates for each tax code based on the levies requested by local taxing districts (schools, municipalities, park districts, etc.) and the total assessed value in those districts. The Clerk also maintains records on tax extensions, rates, tax increment financing (TIFs), and delinquent/forfeited taxes.

Cook County Treasurer’s Office
Issues and collects the property tax bills, posts payment status, manages refunds and overpayments, and administers certain savings and senior programs.

All of this data is brought together for taxpayers in one online hub, the county’s property tax portal, which lets you search by Property Index Number (PIN) or address, see tax history, check exemptions, and more in one place. That central access point is the Cook County Property Tax Portal.

Find your Cook County property tax details in minutes online

A lot of questions about Cook County IL property tax can be answered as soon as you pull up your specific property record online.

The county assigns each parcel a 14-digit Property Index Number (PIN) that acts like a unique ID for tax purposes. When you look up your property, you can usually see:

Current and prior years’ billed tax amounts (often up to a five-year history)

Payment status and ways to pay

A property description (location, classification, estimated value, assessed value, tax rate and tax code, building and lot size where applicable)

Mailing address of the tax bill

Exemptions that have been applied for the last several years

Possible duplicate or overpayment refund opportunities

Recorded documents, deeds, and liens summary

Information about appeals and important deadlines

Use your Property Index Number (PIN) the right way

You’ll get the most complete picture if you search by PIN. You can usually find your PIN on:

Your property tax bill
A recent assessment notice
Most property deeds

When you search by PIN, the portal or office websites can show very detailed data tied directly to that number—tax history, exemptions history, payment status, and more.

If your PIN has changed over time (for example, after a division or consolidation of parcels), the Cook County Clerk’s Mapping Department and the Divisions Department of the Assessor’s Office can help you match old and new PINs and understand how they now map to your property.

Search by address when you don’t know the PIN

If you don’t have your PIN handy, you can still look up Cook County property tax information by address. When you do:

Enter your house number, street name, city, and ZIP code.
Do not include street directions like “N” or “S.”
Do not use abbreviations like “St.” or “Ave.” in the street name field.

Once you’ve located the correct property using address search (often double-checking with the property photo), you can then see the PIN and use it for deeper searches elsewhere, including appeals and Clerk or Treasurer tools.

Pay Cook County property tax on time and in the way that fits you

In Cook County, property taxes are billed in two installments every year:

First installment – Always due March 1. By law, this is 55% of the prior year’s total property tax bill.

Second installment – Mailed after all appeals are completed and tax rates are finalized. The due date can vary each year because it depends on when appeals and rate calculations are finished.

Staying current on these deadlines is critical if you want to avoid interest, penalties, or tax sale activity on your property.

See what you owe and make a secure online payment

The Treasurer’s website puts a lot of key information on a single page. There you can:

See your current amount due
Make an online payment
Download a copy of your tax bill
Sign up to receive tax bills by email
See if your delinquent taxes have been sold
View local governments’ debt and pensions tied to your property

You can do all of that from the page where you can check your payment status or make an online payment.

You’ll typically search using your PIN or your property address, then choose how you want to pay. The Treasurer also provides information on paying by mail, in person, at designated banks, and by ACH or wire transfer if you manage multiple parcels.

Other ways to pay your property tax bill

Besides online payments, the Treasurer’s site explains how to:

Pay by mail using the payment coupon on your bill
Pay at certain bank branches, such as major banks or participating community banks
Request a duplicate tax bill if you misplaced your original
Learn about payment options if you’re dealing with prior-year bills

If you’re struggling to pay the full amount, check the Treasurer’s News and Important Dates sections to see if there are payment plan options or other relief programs active for the current tax year.

Cut your Cook County property tax with exemptions and deferrals

One of the most important ways to manage your Cook County property tax burden is to make sure you’re receiving every exemption you qualify for.

The Assessor’s Office administers homeowner-related exemptions that reduce the equalized assessed value (EAV) of your property for tax purposes. These savings show up directly on your tax bill and can be significant.

The Assessor provides detailed descriptions, qualifications, and forms for these programs on its exemptions overview and forms page.

Core homeowner and senior exemptions

Here are some of the main exemptions mentioned in county materials:

Homeowner Exemption
Available if you own (or have a qualifying lease/contract for) the property and it is your principal residence for the tax year in question. If it’s your first time, you need to apply; once granted, it usually renews automatically.

Senior Citizen Exemption
Reduces the EAV of a qualifying residence for seniors who are 65 or older during the tax year, own or are responsible for the property taxes, and occupy the property as their principal residence. This savings appears as a deduction on the second-installment bill.

Senior Freeze Exemption
“Freezes” the EAV at a base year for qualifying seniors so future increases in EAV do not raise that portion of the bill. It does not freeze the overall tax bill, because tax rates and levies can still change.

Persons with Disabilities Exemption
Provides an annual reduction in EAV for qualifying disabled homeowners.

Disabled Veterans’ Homeowner Exemptions
Offer reductions (and in some cases full exemption) for veterans with certified service-connected disabilities. The reduction depends on the level of disability.

Home Improvement Exemption
Lets you increase your home’s value with up to a certain dollar amount in improvements without raising your property taxes for at least four years. This is typically triggered automatically when a building permit is issued for qualifying improvements.

Many of these exemptions can stack—so a homeowner who is a senior and disabled veteran, for example, may qualify for multiple savings lines on the bill.

Special property tax relief programs

In addition to standard exemptions, Cook County property tax materials describe programs that can help with cash flow:

Returning Veterans’ exemption – Short-term EAV reduction for veterans returning from active duty in armed conflict.

Senior Citizen Real Estate Tax Deferral Program – A State of Illinois program administered locally by the Treasurer that can pay up to a set amount each year on behalf of qualifying seniors as an interest-bearing loan, repaid later (often when the property is transferred).

Property tax relief for military personnel – Administered through the Treasurer’s Office, with dedicated forms.

If you think you qualify for a program you’re not currently receiving, it’s worth checking both the Assessor and Treasurer websites and, if needed, contacting their offices for guidance on forms and deadlines.

Fix errors, missing exemptions, and property data problems

Even if you pay on time, mistakes can creep into your Cook County property tax record. Common issues include:

A missing exemption for one or more tax years

Incorrect property characteristics (wrong square footage, number of units, or building type)

An assessment that doesn’t reflect changes like demolition, vacancy, or unusual conditions

When you review your property online, you should see a five-year history of exemptions applied to your PIN. If something is missing, or your property characteristics are wrong, you may be able to fix it.

Correct property characteristics and assessed value

To confirm that the county’s description of your property is accurate:

Use the Assessor’s site to look up your PIN and review property details.

Compare the county’s data to reality: building size, number of apartments, use type, construction type, etc.

If you spot errors, the Assessor allows owners to request corrections to the property record.

In many cases, a correction is handled through a Certificate of Error, which adjusts an assessment for prior years when a mistake is documented. Forms and instructions for this process are available on the Assessor’s Certificates of Error page.

Keep in mind that, according to current notices from the Assessor, some valuation-related Certificates of Error may be delayed in processing or refunding. Refund timing is handled through the Treasurer’s Office once a Certificate of Error has been approved.

Request a refund when you paid too much

Over time, it’s not unusual for owners to:

Accidentally pay the same installment twice
Overpay due to an escrow or mortgage company payment plus an owner payment
Become entitled to a refund after a successful appeal or Certificate of Error adjustment

The Treasurer’s website offers an Overpayment Refund Search tool where you can look up your PIN and see if there are refunds or uncashed checks waiting. That page also explains how to apply for refunds and check the status of prior refund requests.

Appeal your Cook County property assessment step by step

If you think your Cook County IL property tax bill is too high, one of the most powerful tools you have is the appeal process. Appeals do not challenge the tax rate; instead, they challenge the assessed value of your property or the accuracy of its characteristics.

You can appeal at two main levels:

With the Cook County Assessor’s Office
With the Cook County Board of Review

You may appeal with one or both offices, depending on timing and your situation.

When to appeal with the Assessor

The Assessor publishes an assessment calendar that shows when each township in Cook County is open for appeals. During your township’s appeal window, you can:

Review comparable properties
Submit evidence that your property is over-assessed compared to similar properties
Point out errors in property characteristics or classification
Upload supporting documents, such as appraisals or photos

The Assessor accepts appeals online. You can file an appeal online with the Assessor, track your appeal, and later view appeal history and results.

If the Assessor reduces your assessment, that lower value will feed into the next tax bill, potentially reducing what you owe. In some cases, successful appeals can also trigger retroactive adjustments combined with Certificates of Error.

When to appeal with the Board of Review

If you miss the Assessor’s deadline, or if you disagree with the Assessor’s decision, you may still appeal to the Cook County Board of Review during its separate appeal period.

The Board of Review:

Has its own rules and filing deadlines
Allows you to file online and upload supporting evidence
Publishes decisions that you can search and review later

You can start the process and manage your case through the Cook County Board of Review appeal portal.

Because both offices are independent, some owners appeal at both levels to make sure their assessment reflects current market conditions, especially in years when values or tax bills jump significantly.

Decode Cook County tax rates, tax codes, and local taxing districts

Even if your assessment is correct, your tax rate can still make your bill feel high. Cook County property tax bills include:

A Tax Code – a composite code representing all the taxing agencies (school district, municipality, county, park district, etc.) that levy taxes on your property.

A composite tax rate – the sum of all those individual rates.

Your bill lists each taxing body and its rate. If you want to dig deeper into how those rates are calculated and how they’ve changed, the Cook County Clerk maintains detailed public information.

To see explanations of tax extension terms, rates, and related reports, you can visit the Clerk’s tax extension and rates section. From there, you can:

Look up tax agency rate reports
See how levies and assessed values interact to create the rate in your tax code
Learn more about TIF (Tax Increment Financing) districts and how they affect revenues

This is especially useful if you’re trying to understand why your tax bill went up even though your home’s market value or assessment went down. Often, increases in local tax rates or changes in levies are the reason.

Watch for delinquent taxes, tax sales, and redemption deadlines

Falling behind on Cook County property tax payments can trigger serious consequences, including tax sale and, eventually, loss of the property if taxes are not redeemed.

Key things to monitor:

Delinquent taxes and tax sales – The Clerk’s Office provides information on delinquent property taxes, forfeited taxes, and redemption procedures. You can use its delinquent property tax search page to see if taxes on a property have been sold or if there are outstanding delinquent amounts.

Estimates of the cost of redemption – When taxes have been sold, you can request an Estimate of the Cost of Redemption through the Clerk’s Real Estate & Tax Services Division. This tells you exactly what you must pay (including penalties and fees) to redeem the sold taxes.

Forfeited or open taxes – Owners can request calculations to satisfy forfeited or open items from prior years and pay them in full. There are no payment plans for redemption; everything must be brought current.

Because penalties accumulate and deadlines are strict, it’s smart to use the Treasurer’s and Clerk’s tools early if you think you might miss a due date. Keeping track of your status online and responding quickly to any notices greatly reduces the risk of losing your property rights over unpaid taxes.

Property tax departments and offices – official contacts

Cook County Treasurer’s Office — 118 North Clark Street, Room 112, Chicago, Illinois 60602 — (312) 443-5100

Office of Cook County Treasurer Maria Pappas — 118 North Clark Street, Room 212, Chicago, Illinois 60602 — (312) 603-6202

Cook County Clerk’s Office Real Estate & Tax Services Division — Cook County Building, 118 N. Clark St., Room 434, Chicago, IL 60602

Cook County Clerk’s Mapping Department — (312) 603-5640

Cook County Assessor’s Office — (312) 603-7509

Cook County Assessor’s Office Taxpayer Services Department — (312) 443-7550

Cook County Board of Review — (312) 603-5542

Cook County Property Tax FAQs

How do I look up my Cook County property tax bill and PIN?

You can look up your bill and 14-digit Property Index Number (PIN) online using the county’s one-stop Cook County Property Tax Portal. Search by PIN or by property address to see billed amounts, a five-year tax history, property description (location, class, estimated value, lot/building size), and the tax bill mailing address. If you don’t know your PIN, use the “Search by Property Address” option and always double-check the photo and details to be sure you’re viewing the right parcel.

What are my options to pay Cook County property taxes?

Most owners pay electronically through the Cook County Treasurer’s online payment page, where you can search your property, pay the current bill, and download a copy of the tax bill. Payments can also be made by mail or in person, and the Treasurer’s site explains how to pay at participating banks and via ACH or wire. Cook County bills in two installments each year; the first installment is 55% of the prior year’s total bill, and the second installment is issued after appeals are completed and tax rates are calculated.

How do I check or fix exemptions that lower my tax bill?

Homeowner, Senior, Senior Freeze, Persons with Disabilities, Veterans, and Home Improvement exemptions are administered by the Assessor. You can review exemption descriptions, qualifications, and required forms on the Cook County Assessor’s exemption forms page. If you discover a missing exemption for a prior year, you generally apply for a Certificate of Error through the Assessor so the Treasurer can issue an adjusted bill or refund.

What if I can’t afford my current tax bill or I’m behind?

The Treasurer periodically offers installment options, such as a multi-month payment plan, which are explained on the Treasurer’s site along with due dates and late-payment consequences. For eligible seniors, the State of Illinois’ program administered locally—the Senior Citizen Real Estate Tax Deferral Program—can pay up to a set amount of taxes as an interest-bearing loan, helping prevent loss of the home. You can also use the Treasurer’s tools to see whether taxes have been sold and what steps are needed to redeem them.

Where can I see tax rates, TIFs, and local government debt tied to my property?

To understand why your bill changed, review tax rates and special districts affecting your property. The Cook County Clerk publishes tax extension terms and composite tax rates for each tax code on its Tax Extension and Rates page, and provides detailed information on Tax Increment Financing (TIF) districts. The Treasurer also offers interactive tools on its site that show 20-year tax history and taxing-district debt levels connected to your property, giving you a clearer picture of how local budgets impact your bill.