DuPage County covers much of Naperville along with Wheaton, Lombard, Downers Grove, Lisle, Glen Ellyn and the other suburbs west of Chicago. For most owners here, the DuPage County property tax bill is one of the biggest yearly costs, and several separate offices decide what you owe. This page explains who does what, when bills fall due, which exemptions exist and how to challenge an assessment.
Who does what
| Office | Role |
|---|---|
| Township assessors (nine in DuPage) | Calculate the first assessed valuation and keep a local property database |
| Supervisor of Assessments | Advises assessors, equalizes values, keeps exempt-property records, mails assessment change notices and serves as clerk to the Board of Review |
| Board of Review | Hears assessment complaints and acts on homestead exemptions |
| County Treasurer | Mails one bill with both installment coupons and collects payments; it does not determine values |
State law gives DuPage township assessors until November 15 to finish their assessments, later than most Illinois counties. That is why notices and appeal windows here run from late summer into winter, township by township, and why written Board of Review decisions usually arrive the following March.
Bill cycle and due dates
Illinois bills property tax in arrears, so the bills paid in 2026 were for 2025. DuPage's installments were due June 1 and September 1, 2026, and a late payment adds a penalty of 1.5% of the tax due per month. Dates can change, so read the coupons on your own bill and check the Treasurer's site each spring. Unpaid taxes can end up at the annual tax sale, so a missed bill deserves prompt attention.
Exemptions worth checking
- General homestead: up to $8,000 off assessed value for an owner-occupied home in counties that border Cook, which includes DuPage ($10,000 in Cook, $6,000 elsewhere).
- Senior homestead: up to $8,000 off for owners 65 and older in Cook and its neighboring counties.
- Senior assessment freeze: holds the base value for owners 65 and older under a household income limit that rises to $75,000 for the 2026 assessment year (taxes payable 2027).
- Disability, veterans and returning veterans: separate exemptions, each with its own proof rules.
Appealing an assessment
Review your property record with the township assessor first. If you still think the value is too high, file with the Board of Review inside the 30 days after your township's roll is published. DuPage uses online filing and asks for at least three comparable properties; late filings are rejected. You can take a Board of Review decision to the Illinois Property Tax Appeal Board within 30 days of its postmark.
Sales tax and the community
DuPage sits in the regional transit district. Starting August 1, 2026, the transit part of the sales tax rose by 0.25 points to 1.00% on general merchandise and qualifying groceries and drugs, so check the state's tax rate finder for your exact combined rate.
About 59,700 DuPage residents identify as Asian Indian alone or in combination, roughly 6.4% of the county (American Community Survey, 2020 to 2024), and we regularly help with US-India tax treaty questions. Cities here include Naperville, Wheaton, Lombard, Downers Grove, Lisle, Glen Ellyn, Westmont, Woodridge, Warrenville, Oak Brook and Hinsdale.
How we can help
For homeowners, we can check whether your exemptions are in place, help you weigh whether an appeal is worth filing, and explain how property tax fits into the state and local tax deduction. For landlords and business owners, we handle returns, bookkeeping and payroll, and build property tax into tax planning. For anything specific to your property, talk with a qualified professional.
Frequently asked questions
When are DuPage County property taxes due?
For 2025 taxes billed in 2026, the installments were due June 1 and September 1, 2026. The Treasurer sends one bill with both coupons, normally in spring.
Does the Treasurer set my property tax?
No. The Treasurer collects and distributes the money. Values come from the assessment process, and rates come from the local taxing districts that levy the taxes.
Can I appeal if my assessment seems too high?
Yes. Talk with your township assessor first, then file with the Board of Review inside the 30-day window. An appeal covers the assessment, not the size of the bill.
Do exemptions renew on their own?
Some do and some do not. The disability exemption and the senior freeze, for example, need regular applications, so confirm with your township assessor.
Official sources
- DuPage County Treasurer
- U.S. Census Bureau: ACS 2020-2024 5-year, Table B02018 (DuPage County)
- DuPage County Supervisor of Assessments
- DuPage County: assessment appeal process
- Illinois Department of Revenue: property tax relief programs
This page is a plain-language summary. The official source controls if there is any difference.
General information only, not tax, legal or accounting advice for your situation. Rules, limits and deadlines change; confirm the current rules with the official source or a qualified professional before you act. Reading this page does not create a professional relationship with CPA Tax Payroll and Accounting Corp.