Updated November 2026. Checked against Cook County Clerk, Treasurer and Assessor pages and the Illinois Department of Revenue.
A real estate PIN, or Property Index Number, is the ID an Illinois county gives each parcel. As of November 2026, a Cook County PIN has 14 digits in the pattern AA-SS-BBB-PPP-UUUU, like the Clerk’s sample 12-26-328-009-0000. Find yours on your tax bill or deed, or search your address on the county assessor’s site.
Outside Cook, your county’s supervisor of assessments or treasurer has the same lookup.
Jump to: 🏠 What a PIN is · 🪜 Find yours · 📍 Cook County · 💲 How it’s taxed · ❓ FAQ
Key takeaways
- A Cook County PIN is a unique 14-digit number for each piece of real estate, including vacant lots, parking spaces and condo common areas.
- The Cook County Clerk assigns PINs. The Treasurer says to match the PIN on your bill to the PIN on your deed.
- Outside Cook and other large classifying counties, property is assessed at 33 1/3% of fair cash value.
- The Illinois Department of Revenue doesn’t run property tax. Your county and local districts do.
What is a real estate PIN (Property Index Number) in Illinois?
The PIN is the ID your county uses for one piece of real estate. Cook County’s Treasurer describes it as a “unique 14-digit sequence number” assigned to the legal description of each property. It’s used for assessments, tax rates and tax collection.
Here’s the key idea. A PIN belongs to the property, not to you. The Treasurer compares it to a Social Security number for your home. If you pay taxes on the wrong PIN, the taxes on the one you own are still unpaid.
You may see it called a property identification number too. All of these mean the same thing:
- PIN or Property Index Number.
- Parcel number or parcel ID.
- Property tax ID or tax number.
How do you read a Cook County PIN?
The Cook County Clerk says the PIN is a 10-digit base plus a four-digit unit suffix for condos and leaseholds. Each group narrows the location down a step.
| Part | Digits | Meaning | In the sample 12-26-328-009-0000 |
|---|---|---|---|
| AA | 2 | Area (township) | 12 |
| SS | 2 | Subarea (section) | 26 |
| BBB | 3 | Block | 328 |
| PPP | 3 | Parcel | 009 |
| UUUU | 4 | Unit, for condos and leaseholds | 0000 (not a condo) |
Four zeros at the end mean the parcel isn’t a condo or leasehold. Other Illinois counties use their own formats, so copy the number exactly as your bill shows it.
Is the PIN the same as the IL-PIN for income tax?
No. That’s a common mix-up. If you came here looking for the IL-PIN used with your state income tax return, that’s a Department of Revenue code tied to you, not your house. You can look that one up through the state’s PIN Inquiry Site on MyTax Illinois. For other state services, start at the Illinois official website.
Property index number lookup: how do I find my PIN?
You can look up your property index number for free in five places, quickest first.
- Your property tax bill. The PIN is printed on every bill.
- Your deed. Most recorded deeds list it next to the legal description.
- The county assessor’s search. In Cook County, search by address on the assessor’s site.
- Your closing papers. The title commitment and settlement statement both show it.
- The County Clerk. If your deed has only a legal description, the Clerk’s office can find the PIN.
Outside Cook County, go to your county’s website and look for the supervisor of assessments, the treasurer or a GIS parcel viewer. Most counties let you search by address or owner name for free.
How do Cook County PINs work?
Cook County is where most PIN searches start. The Cook County Assessor’s address search lets you look up a home by street address. It also lets you search by the full 14-digit PIN, or by a 10-digit or 8-digit version. Each condo unit has its own PIN, so a shorter search can help when you don’t know the unit’s number.
Can a Cook County PIN change?
Yes. The Treasurer says that when a property is divided, each new parcel gets a new legal description and a new PIN. So check your PIN after you buy a new house, townhouse, loft or condo. In some cases, parking spaces get one too.
Should I check my PIN if my mortgage pays the taxes?
Yes. The Treasurer says you need your PIN to confirm your mortgage company is paying the right bill. It’s worth checking after a refinance or when you pay off your loan and take over the taxes.
The Cook County Clerk’s office assigns PINs. The Treasurer’s site lets you pay and look up past bills.
How is Illinois property taxed?
The Illinois Department of Revenue says it doesn’t administer property tax. Counties, cities and local taxing districts do. Your county assessor sets the value, and local districts set the rates.
State law says property is valued at 33 1/3% of its fair cash value. The exception is counties with more than 200,000 people that classify property, which is how Cook works. Here’s what 33 1/3% means on three home values.
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Your final bill also depends on exemptions and local rates. Read your bill line by line, and look up exemptions with your county before you buy.
Selling? You’ll need your PIN for the listing and title search
The MLS listing, the title search, the buyer’s lender and your attorney will all use the PIN. Match it to your deed before you list, especially for a condo or a home with a separate parking PIN.
Beycome lists Illinois homes on the MLS for a flat fee, with $0 at closing to Beycome, and you keep control of price, showings and offers. See the plans on our Illinois flat fee MLS page. See how to list your Illinois home on the MLS by owner, read our Illinois FSBO guide, or the one for selling in Chicago without a realtor. If a buyer comes to you directly, here’s how to draft an Illinois FSBO contract. When you’re ready, start your flat fee MLS listing.
Looking up land in another state? See our guides to the Minnesota parcel ID and New York property tax records.
Closing in Illinois? Beycome Title handles title and closing in Illinois, with Prepaid Pricing of $599 at checkout (instead of $995).
Illinois PIN FAQ
Where do I find my property index number?
On your property tax bill and usually on your deed. You can also search your address on your county assessor’s site.
What is my property index number?
It’s the county’s ID for your parcel, printed on your tax bill and usually your deed. In Cook County it has 14 digits, like 12-26-328-009-0000.
How many digits is a Cook County PIN?
Fourteen. The assessor’s site also accepts 10-digit and 8-digit searches.
What is a real estate PIN?
It’s the Property Index Number, the county’s ID for one piece of real estate. It’s assigned to the property, not to the owner.
Who assigns PINs in Cook County?
The Cook County Clerk’s office. If your deed shows only a legal description, the Clerk can find the PIN.
Is my property tax ID the same as my PIN?
Yes, for real estate in Illinois. Forms that ask for a property tax ID mean the PIN.
Does the Illinois Department of Revenue have my property tax records?
No. It doesn’t run property tax. Your county assessor, clerk and treasurer keep the records.
Do I need my PIN to sell my house in Illinois?
Yes. The MLS listing, the title search, the contract and the deed all use it. Match it to your deed before you list, including any separate parking PIN.
Reviewed by Beycome Brokerage Realty LLC, a licensed real estate brokerage. Licenses are listed at beycome.com/faq/how-to/are-you-a-licensed-broker/.
PIN details come from the Cook County Treasurer and Cook County Assessor sites; the 33 1/3% rule from 35 ILCS 200/9-145. Read on October 21, 2026; the PIN structure from the Cook County Clerk, read November 1, 2026. Rules differ in Cook and other classifying counties.
Beycome prices are as of November 2026 and can change. Beycome Title Prepaid Pricing applies in Illinois. “$0 at closing” means no Beycome fee at closing. Other closing costs, taxes, attorney and title fees, and any buyer’s agent pay you agree to still apply.
This is general information, not legal or tax advice.
Sources
- Cook County Treasurer, about your Property Index Number (PIN).
- Cook County Assessor, property search.
- Cook County Clerk, about the Property Index Number (PIN), read November 1, 2026.
- 35 ILCS 200/9-145, statutory level of assessment.
- Illinois Department of Revenue, property tax.
- Beycome, listing package features, October 2026.
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