Kane County property tax appeals: 2026 deadlines have passed. How to get ready for 2027

Your 2026 property assessment in St. Charles, Geneva or Batavia was set months ago, and the window to challenge it at the county level has already closed for all three townships. If your notice made you wince, the useful move now is to understand how the system works so you are ready the next time your township's roll is published.

Who sets your assessed value

In Kane County, each of the 16 townships elects its own assessor, and that office develops the first valuation for your home. The county Supervisor of Assessments then applies an equalization factor so values across the county land at the level state law requires.

For most homes, the target is 33.33% of fair cash value as of January 1 of the assessment year. For 2026, that means a January 1, 2026 valuation date, built from sales in 2023, 2024 and 2025. Batavia Township's assessor notes that sales or appraisals dated after January 1, 2026 can't be considered until the 2027 assessment year.

A quick self-check from the county: divide your assessment by the median level of assessment. The result should be close to what you think your home would sell for.

The 2026 dates for the Tri-Cities townships

The county's 2026 progress report lists these dates:

• St. Charles Township: notices mailed June 16, roll published June 18, Board of Review filing deadline July 20. Final equalization factor 1.0662.
• Geneva Township: notices mailed July 14, roll published July 16, filing deadline August 17. Final equalization factor 1.0703.
• Batavia Township: notices mailed July 28, roll published July 30, filing deadline August 31. Final equalization factor 1.0594. Batavia Township also asked owners to submit comparable sales to the assessor by August 26.

All three deadlines have passed. Township lines don't always follow city limits, so confirm your township with the county's online property search before you plan for next year.

How an appeal works

Step one is a conversation with your township assessor's office. Many questions get settled there.

If you still disagree, you can file a complaint with the Kane County Board of Review. By state law you have 30 days after your township's assessment roll is published in a local newspaper. The Board has three appointed members and can raise, lower or confirm an assessment.

The county lists three grounds for a complaint:

• Physical data: the records show the wrong square footage, lot size or features.
• Valuation: your equalized assessed value is more than one third of your home's fair cash value.
• Equity: your assessment is higher than comparable homes in your neighborhood.

What doesn't work: arguing that your taxes went up, or that your value rose by a certain percentage. The county says the state Property Tax Appeal Board has consistently rejected those as grounds.

Batavia Township's assessor also points out that you do not need to hire an attorney or a tax appeal firm to ask for a reduction.

If you already filed

If you are not satisfied with the Board of Review's decision, the next stop is the Illinois Property Tax Appeal Board. Its FAQ says an appeal must be filed within 30 days of the postmark date on the Board of Review's written decision.

If you missed it

The county is direct about this: once your tax bill arrives, it is too late to challenge that year's assessment unless you already went to the Board of Review. Your next chance is the 2027 roll. The county has not published 2027 dates yet.

Two things you can do today:

• Get an email alert. Subscribe on the Kane County assessments site and you will be notified when your township's roll is published, which starts the 30-day clock.
• Check your exemptions. The county suggests calling to confirm you receive every homestead exemption you qualify for. Exemptions lower your taxable value no matter what your assessment is.

Who to call

• Kane County Assessment Office: 630-208-3818, 719 S. Batavia Ave., Building C, Geneva. Monday to Friday, 8:30 a.m. to 4:30 p.m.
• Batavia Township Assessor: 630-879-1323
• Geneva Township Assessor: 630-232-3600, 400 Wheeler Dr., Geneva
• St. Charles Township Assessor: 630-584-2040