Property owners have an annual opportunity to appeal their assessments to the DuPage County Board of Review. The period during which an appeal may be filed begins on June 10th of the assessment year, and ends September 10th or thirty days after the publication of the township assessment roll, whichever is later.

An assessment appeal does not address the amount of the property tax bill, it is an attempt to prove that the assessed value overstates the property's market value, or is higher than the estimated value of similar properties.

Property owners who question their assessments are encouraged to first call or visit the Assessor's office to review the information in their property files. The Assessor or his staff will provide sales information, and will help homeowners locate similar properties to verify assessment uniformity.

If the property owner still believes that his/her property is overassessed, he/she may file an assessment appeal.

A property owner must provide evidence to support his/her assessment appeal. This evidence should include three (or more) comparable properties. These comparables should be similar properties to the subject, preferably within the same neighborhood.  The comparables should be entered on the Residential Assessment Appeal Form, which can be found on the Forms and Documents page at the Supervisor of Assessments website.  

If the appeal is based on market value, the comparables must be properties that sold during the three years prior to the assessment date.  For example, an appeal of the 2023 assessment would be based on sales from 2020 to 2022.  If the appeal is based on assessment uniformity, the comparables should be similar-sized properties with comparable features. The Assessor's staff will also compile sales and/or uniformity comparables to present to the Board of Review. 

After the appeal deadline, Board of Review hearings are scheduled. Board of Review hearings are held at the DuPage County Government Center, 421 N. County Farm Road, Wheaton.
At the hearing, the appellant is given the opportunity to explain his/her case. The Assessor or a Deputy Assessor will respond, and present an analysis of both the Appellant's Comparables and the Assessor's Comparables.

The Board of Review may ask questions of the appellant and the Assessor. After the hearing, the Board will render a decision. The decision is mailed to the property owner after all Board of Review action is completed for the tax year.

If a property owner is not satisfied by a decision of the Board of Review, he/she may then appeal to the Illinois Property Tax Appeal Board, or to the Circuit Court.