If you own a home in Aurora and believe it’s assessed for more than it’s worth, you can file an Aurora property tax appeal with the Board of Review in the county where your home sits. Aurora straddles the Kane–DuPage line, so the office you file with depends on your address. Either way, the clock is short: 30 calendar days from the date your township’s assessment list is published.1Illinois General Assembly. Illinois Code 35 ILCS 200/16-55 Miss the window and you wait a full year.
Illinois law requires residential property to be assessed at 33 1/3 percent of fair cash value, so even a small overvaluation inflates your bill for years.2Illinois General Assembly. Illinois Code 35 ILCS 200/9-145 – Statutory Level of Assessment A successful appeal lowers the starting assessed value, and that reduction carries through the equalization factor, exemptions, and tax rate into every bill until the next reassessment.
Which County Handles Your Appeal
Aurora properties in townships such as Aurora and Batavia are assessed through Kane County. Properties in townships like Naperville and Wheatland fall under DuPage County. Your township assessor sets the fair cash value as of January 1 of the assessment year, and the Illinois Department of Revenue later applies a county-wide equalization factor to produce your equalized assessed value.3State of Illinois. 2025 Cook County Tentative Multiplier Announced Appeals challenge the assessed value, not the tax rate or the equalization factor.
Pick the Right Ground for Your Appeal
Illinois recognizes three main grounds, and the one you choose dictates the evidence you’ll need.
Overvaluation
Your assessed value, when backed out of the 33 1/3 percent formula, implies a market value higher than what comparable homes are actually selling for. Fair cash value under Illinois law means the price a willing buyer would pay a willing seller in a normal sale.4Illinois Department of Revenue. Publication 136, Property Assessment and Equalization
Lack of Uniformity
The Illinois Constitution requires similar properties to be assessed at comparable percentages of their value.5Illinois General Assembly. Illinois Constitution Article IX – Revenue If neighboring homes with similar features carry lower assessment-to-sale ratios than yours, you have a uniformity claim even when your raw dollar figure isn’t dramatically off.
Factual Errors
The assessor’s records show the wrong square footage, an extra bathroom, a finished basement that’s actually unfinished, or a garage listed as attached when it’s detached. These errors are often the quickest to resolve because the fix is objective.
Evidence That Carries Weight
Boards of Review decide on evidence, not argument. Three categories do the work.
Comparable properties. Pull at least three homes near yours that share age, style, size, and lot dimensions.6Batavia Township. How to File an Assessment Complaint For an overvaluation claim, use comps that sold recently for less than your implied value. For a uniformity claim, use comps with lower assessment-to-sale ratios. Both counties publish online property search tools where you can pull assessed values and sale histories.
Recent sales. Sales from the past 12 months carry the most weight.7Illinois Department of Revenue. Assessment Appeals – Property Tax A recent arm’s-length purchase of your own home is strong evidence of market value. Family transfers, foreclosures, and short sales generally don’t count.
A professional appraisal. A licensed appraisal dated close to the January 1 assessment date is one of the most persuasive items you can submit.9Illinois Department of Revenue. Assessment Appeals – Property Tax
If your home has condition problems that drag its value, document them. Dated photographs of foundation damage, roof failure, or water intrusion, paired with contractor repair estimates, give the board a concrete number to work with.
Filing in Kane County
Kane County complaints go through the Kane County Assessment Office, which supports the Board of Review. Forms are available from the office directly and have historically been posted on the county’s website.8Kane County Assessment Office. Kane County Assessment Office – Forms Before filing formally, contact your township assessor. Batavia Township, for instance, asks residents to submit comparables informally so the assessor can revisit the value before a formal complaint is docketed.6Batavia Township. How to File an Assessment Complaint
On the complaint form you’ll enter your Property Index Number from your tax bill, the owner’s name and address, and the reduction you’re seeking. A grid on the form holds your comparable properties with their PINs, addresses, assessed values, and sale prices. Attach the full appraisal report rather than referencing it.
Filing in DuPage County
DuPage County’s Board of Review operates under the same statute but requires appeal forms and supporting evidence to be submitted in duplicate.10DuPage County. Appeal Process The board describes itself as an informal venue for resolving assessed value disputes and functions as a quasi-judicial body that can lower or raise assessments based on the evidence presented.11DuPage County. Board of Review For the 2025 tax year payable in 2026, DuPage County mailed its Board of Review decision notices on March 18, 2026. Confirm current timing with the Supervisor of Assessments office, since filing windows move with the publication of each township’s assessment list.
The 30-Day Deadline
You have 30 calendar days from the publication of your township’s assessment list to file a complaint, and the publication typically appears in a local newspaper.1Illinois General Assembly. Illinois Code 35 ILCS 200/16-55 Once that window closes, the Board of Review cannot accept further complaints for that tax year.12Kane County Assessment Office. Kane County Assessment Office – Assessment Complaints
Mail is filed as of the postmark. A private carrier like FedEx or UPS uses the date on the shipper’s tracking label. Electronic filings, where allowed, count as filed when received.1Illinois General Assembly. Illinois Code 35 ILCS 200/16-55 You can also walk paperwork in during normal business hours at the relevant county assessment office.13Kane County Assessment Office. Kane County Assessment Office
After You File
The Board of Review first checks that your filing meets its procedural rules. If something’s missing, you’ll receive a notice identifying the deficiency and get at least 10 business days to correct it.1Illinois General Assembly. Illinois Code 35 ILCS 200/16-55 Then the board schedules a hearing and mails you written notice of the date.
Hearings are short and focused on the evidence you already submitted. Some boards allow participation by phone or video. You don’t need a lawyer, and most homeowners handle this stage themselves. The board members review your comparables, any appraisal, and the assessor’s records, then issue a written decision stating whether your assessment was reduced, kept the same, or raised. The board cannot raise an assessment without first giving you notice and a chance to be heard.1Illinois General Assembly. Illinois Code 35 ILCS 200/16-55 DuPage County typically mails its decisions on a single date; Kane County issues decisions on a rolling basis as each township’s window closes.
If the Board of Review Says No
You can take an unfavorable decision to the Illinois Property Tax Appeal Board, a statewide quasi-judicial body that provides independent review.14Property Tax Appeal Board. Property Tax Appeal Board The petition must be filed within 30 days of the postmark on the Board of Review’s decision notice.15Illinois General Assembly. Illinois Code 35 ILCS 200/16-160
PTAB uses its own residential appeal form with a grid for up to nine comparable sales or assessments.16State of Illinois – Property Tax Appeal Board. Residential Appeal Its jurisdiction is limited to determining the correct assessed value on the weight of the evidence. PTAB cannot review your tax rate, your tax bill amount, or grant exemptions.14Property Tax Appeal Board. Property Tax Appeal Board Decisions can take several months.
A Note on Exemptions
An appeal challenges the assessed value. Exemptions, by contrast, reduce your equalized assessed value directly, and you can pursue both at once. If you own and occupy your Aurora home as your primary residence, confirm with your township assessor that the general homestead exemption is on your record. Homeowners 65 and older may also qualify for the senior citizens homestead exemption and, if income-eligible, the senior assessment freeze, which locks in your EAV at its qualifying-year level.17Illinois Department of Revenue. Property Tax – Exemption Information (PIO-74) These are worth checking even if you’re not planning to appeal.
When to Bring in Help
Most residential appeals in Aurora are manageable without representation, especially when the issue is a factual error or a clear overvaluation backed by strong comparables. For higher-value properties or complex disputes over classification, property tax attorneys typically work on contingency, taking a percentage of the first year’s tax savings only if the appeal succeeds. Whoever you consider, confirm they handle appeals in your specific county. Kane and DuPage procedures differ enough that local experience matters more than general credentials.