DuPage County property tax bills for the 2025 tax year were mailed on April 29, 2026, and are payable in two installments: the first is due June 1, 2026, and the second is due September 1, 2026. Illinois bills property taxes in arrears, so the bill arriving this spring covers last year’s taxes. Miss either due date and the unpaid amount starts accruing 1.5% interest per month until it’s paid.
When Bills Arrive and When They’re Due
The Treasurer’s Office sends one mailing per year that covers both installments. For the current cycle, 321,773 bills went out on April 29. Expect yours in late April or early May.
You pay in two pieces. The first installment deadline is June 1 and the second is September 1. If either date lands on a weekend or holiday, the deadline shifts to the next business day. Your bill lists the property’s equalized assessed value, any exemptions already applied, and the tax rates charged by each taxing district covering your parcel.
If the bill doesn’t show up by mid-May, don’t wait it out. Non-receipt doesn’t waive the deadline or the late penalty. You’re responsible for paying on time whether the paper bill reaches your mailbox or not.
What Happens If You Miss a Deadline
Any amount unpaid after an installment deadline becomes delinquent and starts accruing interest at 1.5% per month. The charge hits on the first day after the deadline and again at the start of each following month until the balance is paid or the property goes to tax sale. That rate applies in DuPage and every other Illinois county with fewer than three million residents.
The math gets ugly fast. A $6,000 installment left unpaid for four months adds $360 in interest alone. The rate is set by statute, and the Treasurer’s Office has no authority to waive or reduce it. Calling to negotiate won’t help.
The Road to Tax Sale
DuPage County holds its annual tax sale each November for properties with delinquent taxes. The county doesn’t auction your house. Private investors bid on the right to pay your back taxes, competing on the interest rate they’ll charge you to recover that money. Bidding opens at 9% and the lowest bidder wins; if no private buyer bids, the county steps in at 9%.
Here’s the 2026 timeline for anyone still delinquent after September 1:
- Early October: delinquent names and parcel numbers are published in a local newspaper.
- November 2: a $10 fee is added for publication and mailing costs, and any payment from this point forward must be made by cashier’s check, cash, or money order.
- November 18, 4:30 p.m.: the full balance must reach the Treasurer’s Office.
- November 19: the tax sale begins.
After the sale, you have two to two-and-a-half years to redeem the lien, depending on how the property is classified. Redemption means repaying the investor the full tax amount plus their interest and fees. If you never redeem, the buyer can eventually petition for a deed to your property. One silver lining: the lien isn’t reported to credit agencies.
How to Pay
DuPage County accepts payment several ways, and each has a quirk worth knowing.
By mail. Send the payment coupon with a check payable to the DuPage County Collector. The U.S. Postal Service postmark counts as the legal date of receipt, so a letter postmarked June 1 won’t trigger a penalty even if it lands at the Treasurer’s Office a week later.
At a bank. Dozens of banks across the county accept tax payments during the collection window, roughly May through early September. Bring your payment coupon. Some banks accept photocopies, but call first. BMO branches no longer accept cash from non-customers, only checks.
In person. You can pay directly at the county building in Wheaton during business hours.
Online. The Treasurer’s portal takes e-checks and credit cards. Credit card payments carry a 2.10% convenience fee (minimum $3.00) charged by the third-party processor. PIN-based debit cards have a flat $3.00 fee. On a $6,000 installment, 2.10% is $126, so e-check is almost always the better deal. Save the confirmation screen as your receipt.
If Your Mortgage Escrow Pays the Bill
If you have an escrow account, your lender collects tax money through your monthly mortgage payment and pays the county directly. You’ll still receive a copy of the bill from the county for your records, but you generally don’t need to take action on it.
Do not submit a duplicate payment at a bank or online. The Treasurer’s Office warns that overpayments create refund headaches that can take months to sort out.
What you should do is review the annual escrow analysis your lender sends. That statement compares what was collected from you against what was actually paid for taxes and insurance. Verify the tax amount your lender paid matches what the county billed. If there’s a shortage, your monthly payment will go up; if there’s a surplus, you may get a refund or credit. If your mortgage doesn’t include escrow, paying the county on time is entirely on you.
If Your Bill Never Arrived
You can pull up your tax information through the DuPage County property records portal using your Property Index Number. The PIN is a ten-digit number you’ll find on a prior tax bill, your deed, or your closing documents. No PIN handy? The portal also searches by street address.
Once you locate the parcel, you can view and print a duplicate bill with the assessed value, exemptions, tax rates, and payment coupons for each installment. The printable version works just like the original if you need to bring a coupon to the bank. And it bears repeating: not getting the mailed bill does not extend your deadline or waive the 1.5% monthly interest.