Kane County property tax appeal 2027: deadline, forms and how to file
To appeal a Kane County assessment, file with the Kane County Board of Review by mail or in person; in Illinois the deadline is 30 days after the township assessment list is published (Cook County uses township filing windows). Confirm the exact date on your notice or with the assessor; we add each county's 2027 date here when it is published.
Assessment changes are published township by township in local newspapers; for 2026 the Board of Review posted publication dates from June 9 (Dundee) through October 2 (Elgin), 2026, each with its own filing deadline on the Publications page.
Data as of 20 Oct 2026 · Kane County Board of ReviewCheck your own assessment
Free. We compare the value on your notice with recent sales of similar homes nearby and tell you whether an appeal is worth filing. Have your assessment notice and tax bill handy.
By checking an address you agree to the Terms and Privacy Policy. We keep an address only if you add it to a dashboard; we never sell it.
How to file in Kane County
- Step 1
File the appeal
Use the method your notice lists, by the deadline on the notice.
- Step 2 · before the hearing
Prepare and submit your evidence
Overvaluation must be shown by a preponderance of the evidence; a uniformity (equity) claim needs clear and convincing evidence. The strongest evidence is a recent arm’s-length purchase of your home, or an appraisal as of January 1. Otherwise use at least three comparable sales, or for equity at least three similar nearby homes with their assessments and property record cards, in a grid. Bring a photo of your home and its property record card.
- Step 3
Meet, then hear
An informal review with Township assessor or Supervisor of Assessments comes first; if you decline the offer, the Kane County Board of Review hears the case. Most reductions happen at the first step.
Before you file: how to read your notice · evidence that works · informal vs formal hearing · when not to appeal
Forms
| Form | Number | Use | Format |
|---|---|---|---|
| Residential/Farm Assessment Complaint | — | Complaint for residential and farm property (2026 session form) | Fillable PDF |
| Commercial/Industrial Assessment Complaint | — | Complaint for commercial and industrial property | |
| Association Assessment Complaint | — | Complaint filed by a condominium or common interest community association | |
| Multi-Parcel Addendum | — | Addendum listing all parcel numbers when one property has multiple PINs | |
| Residential Appeal (Property Tax Appeal Board) | PTAB-1A | Only after the Board of Review decides: the state appeal, due 30 days after the board’s written notice. Can also be filed online through PTAB eFile. | Fillable PDF |
Appeal levels
| Level | Who hears it | Deadline | Cost |
|---|---|---|---|
| Informal review | Township assessor or Supervisor of Assessments | Before the Board of Review deadline | Free |
| Board of Review | Kane County Board of Review | 30 days after the assessment list is published | Free |
| Property Tax Appeal Board | Illinois Property Tax Appeal Board (state) | 30 days after the Board of Review’s written decision | No filing fee |
| Court | Circuit court (administrative review), or a tax objection in Kane County circuit court | 35 days after the PTAB decision; tax objections follow the tax-bill penalty date | Court costs |
What evidence the board accepts
Overvaluation must be shown by a preponderance of the evidence; a uniformity (equity) claim needs clear and convincing evidence. The strongest evidence is a recent arm’s-length purchase of your home, or an appraisal as of January 1. Otherwise use at least three comparable sales, or for equity at least three similar nearby homes with their assessments and property record cards, in a grid. Bring a photo of your home and its property record card.
Kane County questions
When is the Kane County appeal deadline for 2027?
No 2027 date is published yet. The board’s rule: Complaints must be filed with the Clerk of the Board on or before 30 calendar days after the township's publication date; the Board posts each township's publication date and final filing deadline on its Publications and Deadline pages. Mailed complaints are filed as of the USPS postmark date (other couriers: date on the shipper's tracking label). Evidence must accompany the complaint or be uploaded to the Board's evidence portal no more than 14 calendar days after the township's filing deadline.
How do I appeal my assessment in Kane County?
File the Residential/Farm Assessment Complaint with the Kane County Board of Review, 719 S. Batavia Avenue, Building C, Geneva, IL 60134. Mailed complaints count as filed on the postmark date.
Should I talk to the assessor first?
Yes. The township assessor or the Kane County Supervisor of Assessments can fix record errors informally. Still file with the Kane County Board of Review by the deadline: a board complaint is required before any state appeal.
What evidence works best?
A recent arm’s-length purchase of your home or an appraisal as of January 1. Otherwise, at least three comparable sales, or three similar nearby homes with lower assessments, with property record cards and photos.
How do I contact the Kane County Supervisor of Assessments?
Mail: Kane County Board of Review, 719 S. Batavia Avenue, Building C, Geneva, IL 60134. Phone: 630-208-3818. Hours and walk-in details: assessments.kanecountyil.gov.
What if the Board of Review says no?
Appeal to the Illinois Property Tax Appeal Board within 30 days of the board’s written decision. There is no fee, and you can file online through PTAB eFile. A lowered value on an owner-occupied home carries over for the rest of the assessment period.
Check whether yours is over-assessed
Nearby counties
DeKalb County · DuPage County · Kendall County · McHenry County · Boone County · Lake County · Cook County
- Kane County Assessment Complaints page
- Kane County Board of Review Publications (2026 township publication dates and deadlines)
- Kane County Electronic Evidence Submission page
- Kane County Board of Review hearings page
- Kane County Board of Review 2026 Rules and Procedures (PDF)
- Kane County Residential/Farm Assessment Complaint form (2026)
- Kane County Assessments contact page
- Illinois State Board of Elections County Officers directory
- 35 ILCS 200/16-55 — Board of Review complaints
- 35 ILCS 200/12-10 — Publication of assessments
- 35 ILCS 200/16-160 — Appeal to the Property Tax Appeal Board
- Illinois DOR — Assessment Appeals
- Property Tax Appeal Board — Filing your appeal
- Property Tax Appeal Board — FAQ
- needs_verification: deadlineDate: 2027 township publication dates and filing deadlines are not published yet (the Board posts them by township when assessment changes are published, mid-2027)
- U.S. Census Bureau, county population estimates (2024) and county gazetteer (2024).