How to appeal a DuPage County, IL property assessment
✓ Verified — Last verified October 24, 2026
Filing details published for DuPage County. Match the notice and assessment cycle to the official instructions.
Official appeal instructionsNot tax or legal advice; confirm with your county.
Filing timing
Notice-dependent instructions
File within 30 days after publication of the township assessment roll. Deadlines differ by township.
Official source. Verified .
Where to file
DuPage County Board of Review through SmartFile.
Official source. Verified .
Assessment notice period
Notice mailing and assessment publication dates vary by township; see the county’s current table.
Official source. Verified .
Official offices
DuPage County Supervisor of Assessments
Sources for these instructions
https://www.dupagecounty.gov/government/departments/supervisor_of_assessments/appeal_process.php
The period during which an appeal may be filed ends thirty days after the publication of the township assessment roll.
Verified October 24, 2026
https://www.dupagecounty.gov/government/departments/supervisor_of_assessments/appeal_process.php
You can file a property assessment appeal through the SmartFile appeal e-filing system
Verified October 24, 2026
https://www.dupagecounty.gov/government/departments/supervisor_of_assessments/appeal_process.php
Appeal Process
Verified October 24, 2026
Continue with your property
Common questions
Where do I file a DuPage County assessment appeal?
DuPage County Board of Review through SmartFile.
Updated , from cited verification dates. Individual sources may have earlier checks.