DuPage County property tax bills are mailed in late April, with the first installment due June 1 and the second due September 1. For the 2025 tax year, billed in 2026, the Treasurer’s Office mailed 321,773 bills on April 29, and the two DuPage County property tax due dates are June 1, 2026 and September 1, 2026. Illinois bills property taxes in arrears, so the bill you open in spring 2026 covers your 2025 taxes. Miss either installment and interest starts stacking up immediately at 1.5% per month.
When Bills Arrive and When Payment Is Due
DuPage County sends one mailing that covers both installments. If either due 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 applied, and the rates from every taxing district that covers your parcel. DuPage has roughly 401 taxing entities drawing from property tax collections, which is why a single bill can carry a dozen or more line items.
If nothing arrives by mid-May, don’t wait it out. Non-receipt of the bill doesn’t waive the deadline and doesn’t waive the penalty. Paying on time is your responsibility whether or not the paper bill reaches your mailbox.
Late Payment Penalties
Any unpaid balance after the installment deadline is delinquent and accrues interest at 1.5% per month. That rate applies in DuPage and every other Illinois county with fewer than three million residents. The charge hits the day after the deadline and again at the start of each month that follows, until the balance is paid or the property goes to tax sale.
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.
Tax Sale Timeline If You Don’t Pay
DuPage County holds an annual tax sale each November for properties with delinquent taxes. What gets sold isn’t your house. Private investors bid on the right to pay your back taxes, competing on the interest rate they’ll charge you to recover their money. Bidding starts at 9%, and the lowest bidder wins. If no private buyer bids, the county steps in at 9%.
Here’s how the 2026 calendar runs. If either installment is still unpaid by early October, your name and parcel number get published in a local newspaper. By November 2, a $10 fee is added for publication and mailing, and any payments after that date have to be made by cashier’s check, cash, or money order. The full balance must reach the Treasurer’s Office by 4:30 p.m. on November 18. The sale begins the next day.
After the sale, you have two to two-and-a-half years, depending on property classification, to redeem the lien by repaying the investor the full tax amount plus their interest and fees. The tax sale is a lien sale, not a property sale, but if you never redeem, the buyer can eventually petition for a deed. The lien itself isn’t reported to credit agencies.
How to Get a Copy of Your Bill
If the bill never showed up, the DuPage County property records portal lets you pull your tax information using your Property Index Number. The PIN in DuPage is a ten-digit number based on the Rectangular Survey System that identifies your parcel geographically. You’ll find it on a prior tax bill, your deed, or your closing documents.
No PIN handy? The portal also searches by street address. Once you find your parcel, you can view and print a duplicate bill showing your assessed value, exemptions, rates, and the payment coupons for each installment. The printable version works the same as the original if you need to bring a coupon to the bank.
Ways to Pay
DuPage County accepts payment several ways, each with quirks worth knowing before the deadline.
- By mail. Send your 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 an envelope postmarked June 1 won’t trigger a penalty even if it arrives a week later.
- In person at a bank. Dozens of banks throughout DuPage accept tax payments during the collection window, roughly May through early September. Bring your payment coupon. Some banks accept photocopied coupons, but call ahead to confirm. One detail that catches people off guard: BMO branches no longer accept cash from non-customers, only checks.
- In person at the Treasurer’s Office. You can pay directly at the county building in Wheaton during business hours.
- Online. The Treasurer’s portal accepts 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 card transactions have a flat $3.00 fee. Save the confirmation screen as your receipt.
On a $6,000 installment, the credit card fee works out to $126. E-check is almost always the better deal online.
If Your Lender Handles It
If you have a mortgage with an escrow account, the lender collects tax funds through your monthly payment and pays the county directly. You still get a copy of the bill from the county for your records, but you generally don’t need to act on it. Review the annual escrow analysis your lender sends and confirm the tax amount they paid matches what the county billed. Mistakes happen, and a lender paying the wrong amount can trigger a surprise escrow adjustment later.
One caution from the Treasurer’s Office: if your mortgage company pays your taxes, do not submit a duplicate payment at a bank or online. Overpayments create refund headaches that can take months to unwind. If your mortgage doesn’t include escrow, the county deadlines are yours alone to meet.