Rate Breakdown

Property taxes in Dupage County are calculated by multiplying the assessed value (minus exemptions) by the total local millage rate.

How Property Tax Works in Dupage County

In Dupage County, property tax is calculated based on the assessed value of a dwelling or improvement, the county’s overall millage rate, and any applicable local millages such as the Township or Village levy. The assessment process typically begins in January each year when the Tax Assessor’s Office appraises residential properties at a rate of 100 % for residential and 50 % for commercial structures. Once the market value is determined, the assessor issues an Assessment Notice, which outlines the initial assessed value and the classification of the property. The County Commissioner’s Office then publishes the assessed values in a public index, allowing owners to review and request a reevaluation if they believe the value is too high.

The millage rate represents the amount of tax dollars owed per $1,000 of assessed value. Dupage County’s base rate is split into the County millage (usually around 72 milli‐units) and common‑wealth millages (typically 7 milli‑units). Local municipalities—such as the City of DeKalb or the Village of Hawthorn Woods—add their own millages, often ranging from 30 to 90 milli‑units. Consequently, the total millage rate can vary widely within the county, and the final tax bill is the product of the assessed value, the total millage, and the valuation multiplier (E-rates).

Available Exemptions

Illinois offers several exemptions that can reduce the taxable basis of a property. Dupage County residents can take advantage of:

• Homestead Exemption: Property owners qualify for a $14,500 exemption if the property is their primary residence, subject to specific ownership and occupancy requirements.
• Senior Citizen Exemption (SCE): Homeowners aged 65 or older, or disconnected families with a qualifying member, may receive a $14,500 exemption provided they meet the residency and income thresholds.
• Disability Exemption: Veterans, spouses, or children with disabilities qualifying for state disability assistance can claim a $14,500 exemption.
• Veteran Exemption: Veterans honored for service can secure a $14,500 exemption if they meet criteria regarding active duty, rank, and awards.
• Miscellaneous City Exemptions: Several municipalities in Dupage County offer additional exemptions, such as the “Hawthorn Woods Rural Excess Land” exemption for properties over 2 acres, or the “Chicago‑Area Gaming” credit.

All exemptions require application through the Tax Assessor’s Office. Forms are available on the county website, and deadlines typically align with the annual assessment cycle, usually by March 31st. Proof of eligibility, income statements, or military ID may be needed during submission.

Payment Schedule & Deadlines

Dupage County requires tax payments in two installments:

• First Installment: Due on or before the 31st of March. This payment covers 50 % of the total tax liability.
• Second Installment: Due by the 30th of September, representing the remaining 50 % of the bill.

Owners may pay the full amount by the first deadline (March 31) to avoid any interest. Late payments attract a monthly interest rate of 5 % applied to the unpaid balance, plus a one‑time $50 late‑payment fee for each installment missed. The county also offers a Tax Pay‑Later Plan for homeowners who qualify under a hardship assessment, allowing them to defer payment for the first year with no penalty—but the balance must be paid within 12 months of the deferment period, at a 6 % interest rate.

Appealing Your Assessment

Disputing an assessment in Dupage County is a straightforward process, provided you act promptly:

1. Request a Review: Contact the Tax Assessor’s Office within 30 days of receiving your Assessment Notice to file a formal request for review. Explain why the assessed value appears incorrect and provide supporting documents—such as a recent appraiser report or comparable sale data.
2. County Appraisal Review Board (ARB) Hearing: If the initial review does not result in adjustment, you may request a hearing before the ARB. Hearings are usually scheduled via the county’s online portal, and you are encouraged to bring any third‑party appraisal or evidence. You may represent yourself or hire a qualified attorney.
3. County Board of Appeals: If the ARB decision is unfavorable, the final step is an appeal to the County Board of Appeals. Appeals must be filed within 90 days of the ARB decision and will be heard in a public hearing.
4. Right to a Repeated and Final Appeal: After the County Board of Appeals, you still have the right to appeal to the Division of Appeals in the Department of Local Government Services, but the window narrows to 30 days past the final decision.

Timely action and accurate documentation greatly increase the likelihood of a favorable outcome. Dupage County’s portal provides step‑by‑step guidance and downloadable forms to assist residents throughout the appeals process.