Cook County bills a year behind, in two pieces
Taxes in Cook County are paid in arrears. The bills you pay in 2026 are for tax year 2025. Each tax year comes in two installments.
The first installment is a placeholder. By law it's 55% of the total taxes paid the year before. Exemptions, the new assessment and the new tax rates all land on the second installment. Source: Cook County Assessor, Frequently Asked Questions.
So the second bill is where the year's real number shows up. If your assessment went up, or rates rose in your school or park district, the second installment carries all of it.
2026 due dates, and a second bill that moves
For tax year 2025, the Cook County Treasurer set the first installment due Wednesday, April 1, 2026 and the second installment due Thursday, October 1, 2026. Source: Cook County Treasurer, Important Dates.
The second installment hasn't had a steady date lately. On the Treasurer's list, tax year 2023's was due August 1, 2024 and tax year 2024's was due December 15, 2025.
When the bill is late, your servicer works from an estimate until the real number arrives. If you buy or refinance in that gap, your escrow is set from an older bill.
What escrow does with your tax bill
An escrow account is set up by your lender to pay property-related bills like taxes and homeowners insurance. Part of each monthly payment goes into the account, and your servicer pays the bills from it. Source: CFPB, What is an escrow or impound account?
Your servicer can collect enough each month to cover the year's expected bills, plus a cushion of up to two months' worth of estimated payments. It has to send you an initial escrow statement and then one every year, showing the account's history and a projection for the next year. Source: CFPB, Is there a limit on how much my lender can make me pay into escrow?
Some loans have to have escrow. Federal rules require an escrow account for taxes and insurance on a first mortgage on your home that the CFPB classifies as higher-priced, and the account generally stays for at least five years. Source: CFPB, 12 CFR 1026.35. On other loans, whether you can waive escrow depends on the loan program and your down payment. Ask us before you assume either way.
Why your payment changes after the second bill
Say you close in the spring. Your lender sets up escrow using the latest full tax bill on the home. Then the second installment comes out in the fall, and it's higher than that bill because the assessment went up.
Your servicer pays the bill from escrow. At the next annual escrow analysis, it looks at what it paid and what it collected, and resets your monthly deposit. If the account came up short, there are rules on how it can collect the difference. Source: CFPB, 12 CFR 1024.17 (escrow accounts).
- A shortage of less than one month's escrow payment can be left alone, collected within 30 days, or spread over at least 12 months.
- A shortage of one month's payment or more can be left alone or spread over at least 12 months. It can't be demanded all at once.
- A surplus of $50 or more has to be refunded to you within 30 days of the analysis.
Expect your payment to go up in two ways in that case. The monthly deposit rises to match the new tax bill, and a shortage spread over the year sits on top of it. If you'd rather pay a shortage in one lump sum, ask your servicer whether it allows that.
A higher escrow payment after the first year is common for Cook County buyers. The estimate at closing starts from the seller's bill, and your first full bill can come in higher.
The first-year trap for new buyers
The estimate at closing starts from the seller's last bill, and that bill reflects the seller's exemptions. Exemptions belong to the owner who lives in the home, and they don't move over to you. If you have never received a homeowner exemption on your home, you need to apply for one. The Assessor may mail an application to recent buyers, and you can apply online. Source: Cook County Assessor, Frequently Asked Questions.
Apply as soon as you can after closing. A missed exemption means a bigger bill, and escrow passes that straight into your payment. Our guide to how much house you can afford in Chicago walks through how a Cook County bill is built, so you can see what the exemption is worth on a given home.
New construction and gut rehabs need extra care. The last bill may reflect the property before the work was done, so the first full bill after the reassessment can be a lot bigger. Your attorney can help you estimate it before you write an offer.
Taxes at closing: the seller credit
Since Cook County bills a year behind, the seller will owe taxes for time they owned the home that haven't been billed yet. In Chicago that's usually handled as a credit from the seller to you at closing. The contract says how that credit is figured, and your attorney negotiates it.
The credit lowers your cash to close. It doesn't pay the bill for you. When the bill comes, escrow pays it, or you do if you don't have escrow. Your Loan Estimate also shows the money needed to start your escrow account at closing. Our guide on how to compare Loan Estimates shows where to find it. If you're buying a 2-flat, the tax bill is usually larger, and our 2-flat buying guide covers how it fits into qualifying.
What to check each year
The Cook County Treasurer reminds owners who use escrow that they're still the ones responsible for making sure the tax gets paid. Its checklist is short. Source: Cook County Treasurer, Monitoring Your Mortgage.
- Know whether your taxes are paid through escrow. If you aren't sure, call your servicer before you pay anything, so you don't pay twice.
- After each installment's due date, check the Treasurer's site to confirm the payment posted.
- Confirm the PIN your servicer has on file. Payments sometimes go to the wrong one.
- If you're current on escrow and the servicer pays late or on the wrong PIN, the Treasurer says the lender has to cover the resulting interest or fees, and you should be reimbursed for a payment made on the wrong PIN.
Read the annual escrow statement when it comes too. It shows which tax amount the servicer used. If that figure looks off, call before the new payment starts.
Know your tax and escrow number before you offer.
15-minute conversation. Send us the address and we'll look at its tax history, what changes once you own it, and how escrow would be set up at closing. No SSN, no impact to credit.
Schedule a CallCommon questions about Cook County taxes and escrow
When is the Cook County second installment due in 2026?
The Cook County Treasurer set Thursday, October 1, 2026 as the due date for the tax year 2025 second installment. The first installment for that tax year was due Wednesday, April 1, 2026.
Why is the first installment 55% of last year's bill?
Illinois law sets it that way. The Cook County Assessor says the first-installment bill is 55% of the total taxes paid the previous year. Exemptions and the new year's assessment and rates show up on the second installment.
Why did my escrow payment go up?
Usually because the tax bill came in higher than the estimate your servicer used. At the annual escrow analysis, the servicer compares what it paid out with what it collected and resets your monthly deposit for the next year. If the account fell short, it can also ask you to make up the shortage.
Can my servicer make me pay an escrow shortage all at once?
Only if it's small. Under the CFPB's escrow rule, a shortage of less than one month's escrow payment can be collected within 30 days. A shortage of one month's payment or more can only be spread over at least 12 months, or left alone.
Do I get the homeowner exemption automatically after I buy?
No. The Cook County Assessor says that if you have never received a homeowner exemption on your home, you need to apply for one. The Assessor may mail an application to recent buyers, and you can also apply online.
Should I pay my Cook County tax bill if I have an escrow account?
Check with your servicer first. The Cook County Treasurer warns owners with escrow not to double-pay, and to check online after each due date that the payment was made on the right PIN.