Kane County property tax: rates, appeals, and exemptions explained

Last updated 2026-07-09

How does Kane County property tax work from assessment to bill?

Your tax bill passes through four county offices before it hits your mailbox. Knowing who does what saves you a lot of wasted phone calls when you try to cut it.

The Kane County Supervisor of Assessments oversees the process, but the actual valuing of your house happens at the township level. Kane County has sixteen townships, each with its own elected assessor ^[1]. That assessor estimates the fair market value of your property. State law then requires Illinois counties to assess at 33.33% of that figure, and that number is your Equalized Assessed Value (EAV). Rates apply to the EAV, not to market value.

Once township assessors set values, the Illinois Department of Revenue calculates an equalization factor, sometimes called the "multiplier," to line up county assessments with actual sales statewide. For Kane County, that multiplier has sat near 1.000 in recent years, which means local assessments have tracked the market fairly closely ^[2]. "Fairly closely" is a countywide average, though. Any single property can still be off by 10 to 20%.

The final bill is your EAV times the composite tax rate for your exact tax code area, minus any exemptions you qualify for. Kane County has more than 600 separate tax code areas, because every municipality, school district, and special district draws its own levy ^[3]. Your neighbor one block over, sitting in a different school district, can face a noticeably different rate.

Bills arrive in two installments. The first is due in June and equals 55% of the prior year's total. The second, which reflects rate changes and exemption adjustments, is due in September ^[3]. Miss either date and interest starts at 1.5% per month under 35 ILCS 200/21-15 ^[4].

What are Kane County property tax rates right now?

There is no single Kane County property tax rate. What you pay depends on exactly where your parcel sits inside the county's patchwork of taxing districts.

The overall picture is blunt: Kane County is expensive. The Tax Foundation ranked Illinois second-highest in the country for effective property tax rates in its 2023 data, and Kane County sits above the state median ^[5]. The county's median effective rate for homes has run between 2.6% and 2.8% of market value across recent assessment cycles ^[5].

Township / Area	Approximate Total Rate (per $100 EAV)	Notes
Elgin (City of Elgin portions)	$11.00-$12.50	Elgin school districts drive high rates
Aurora (Kane Co. portion)	$10.50-$12.00	Overlaps with DuPage rates in some areas
Carpentersville area	$10.00-$11.50	Dundee Township
St. Charles	$8.50-$10.00	St. Charles CUSD 303
Geneva	$8.00-$9.50	Lower levy base
Batavia	$8.50-$10.50	Batavia USD 101

These ranges come from Kane County's published tax code rate files. Your exact rate is printed on your tax bill under "tax code" ^[3]. Rates are per $100 of EAV. A home with a $150,000 EAV in an Elgin tax code at $11.50 per $100 pays roughly $17,250 before exemptions.

Compare that to Hennepin County, Minnesota, where effective residential rates run closer to 1.1 to 1.3% of market value. Same house, a fraction of the bill. That gap is why Kane County homeowners feel it.

Rates shift every year as taxing districts set their levies in December. The Kane County Clerk publishes final tax code rates each spring, usually by April ^[9].

How is my Kane County home assessed, and can the value be wrong?

Yes, it can be wrong, and often is. Township assessors in Illinois are elected officials with wildly different staff levels and budgets. Most rely on mass appraisal: statistical models run against large groups of properties at once instead of individual walk-throughs. That works well on the average house and badly on the odd one.

Your township assessor has to assess at 33.33% of "fair cash value" under 35 ILCS 200/9-145 ^[4]. Fair cash value means what a willing buyer pays a willing seller with nobody under pressure. The assessor estimates it from sales of comparable homes, usually looking back 18 to 36 months.

Here is where assessments go sideways. Wrong property record data (bad square footage, wrong bedroom count, a finished basement listed as unfinished). No adjustment for a dying roof or a 1985 kitchen. Comps pulled from a neighborhood that does not match yours. If the model valued your 1960s ranch using sales from a new subdivision two miles away, it almost certainly overshot.

Kane County reassesses every four years on a township-by-township cycle. When your township comes up for its quadrennial reassessment, values jump harder than in off years, and that is exactly when complaints spike. Pull your property record card through the Kane County Supervisor of Assessments online search ^[1], then check every field and compare the assessed value to recent nearby sales before deciding whether to appeal.

One clean test. Divide your assessed value by 0.3333 to get the market value the assessor is assuming. Then find what similar homes near you actually sold for in the last 12 to 18 months. If the assessor's implied value beats those sales by more than 5 to 10%, you probably have a case.

What exemptions can lower my Kane County property tax bill?

Exemptions in Illinois cut your EAV, not your bill directly. But at a $10 rate per $100 EAV, every $1,000 knocked off your EAV saves $100 a year. They stack, and they add up fast.

Here are the main ones available to Kane County homeowners ^[1][4]:

General Homestead Exemption: Cuts EAV by up to $6,000 for an owner-occupied primary residence. You apply once, and it renews automatically as long as you stay eligible. This is the exemption new buyers miss most, because they never realized they had to file.

Homestead Improvement Exemption: Add an addition or a big improvement and the assessed value of that improvement gets frozen for four years, capped at $25,000 in added EAV. Under 35 ILCS 200/15-180 ^[4], it kicks in when the improvement raises EAV by more than $75.

Senior Citizens Homestead Exemption: Homeowners 65 or older get another $5,000 off EAV. Stacked with the General Homestead, that's $11,000 gone from your EAV.

Senior Citizens Assessment Freeze (Senior Freeze): This one works differently. It freezes your EAV at the level it hit when you first qualified, as long as your total household income stays at or below $65,000 a year ^[4]. Values rise, you pay nothing on the increase. You reapply every single year.

Persons with Disabilities Homestead Exemption: $2,000 off EAV, with documentation of a qualifying disability.

Veterans and Returning Veterans: Several tiers, from a $5,000 EAV cut for returning veterans up to a full exemption for veterans with a 100% service-connected disability under 35 ILCS 200/15-165 ^[4].

Applications go to the Kane County Supervisor of Assessments. Most exemptions carry a March 1 deadline for the current tax year, though the Senior Freeze deadline is July 1 ^[1]. Call the office to confirm, since dates move.

One trap people fall into every year. If you bought mid-year, the prior owner's exemptions do not transfer. You have to apply yourself. Plenty of new homeowners eat a full un-exempted bill for a year or two simply because nobody told them.

What is the deadline to appeal Kane County property taxes?

Miss the appeal deadline and you wait a full year. There is no grace period, no soft window, no exception for a good excuse.

The appeal window to the Kane County Board of Review opens once the township assessor's books close each year. Because sixteen townships run on different schedules, there is no single countywide date ^[6].

The pattern goes like this. The township assessor publishes a "list of assessed values" in a local newspaper. The Board of Review complaint period then opens for 30 days from that publication date. In practice, most townships publish and open their windows somewhere between August and October ^[6].

The Kane County Board of Review posts township-by-township schedules each year ^[6]. Check in late July or early August, find your township, and mark the closing date with a week of buffer.

Beyond the Board of Review, you have two more shots. The Illinois Property Tax Appeal Board (PTAB) accepts appeals after a Board of Review decision, with a 30-day window from the date the decision is mailed ^[7]. Circuit court is also open to you, but the legal fees make it impractical for most homeowners.

Appeal Level	Who Hears It	Typical Deadline	Filing Fee
Township Assessor (informal)	Township assessor	Before books close	None
Kane County Board of Review	3-member board	30 days after publication	None
Illinois PTAB	State board	30 days after BOR decision	$10.50 [7]
Circuit Court	Judge	175 days after BOR decision	Court filing fees

The Board of Review is where most homeowners win or lose. It's free, it doesn't need a lawyer, and the standard is one you can meet: show that comparable sales support a lower value.

How do I appeal my Kane County property tax assessment myself?

A DIY appeal to the Kane County Board of Review comes down to five steps. None require an attorney or a contingency firm skimming 30 to 50% of your savings.

Step 1: Pull your property record card. The Kane County Supervisor of Assessments site has an online lookup ^[1]. Print your card and check every field: year built, square footage, bedroom and bathroom count, basement finish, garage size. Errors here are your easiest wins, because the assessor has to fix them no matter what the market did.

Step 2: Find three to six comparable sales. You want homes that closed in the 12 to 18 months before January 1 of the tax year you're appealing. Comps should sit within a mile if possible, within 15 to 20% on square footage, and similar in age, style, and condition. Sources: the Supervisor of Assessments sale search, Zillow sold listings, or Redfin. The Board of Review's own rules spell out what counts as a valid comparable ^[6].

Step 3: Work out the implied market value from your comps. Average the comp sale prices. Multiply by 33.33% to get the EAV those sales imply. If that number lands below your current EAV, you have a starting case.

Step 4: Fill out the Board of Review complaint form. Download it from the Kane County Board of Review page ^[6]. You'll need your parcel index number (PIN), your current assessed value, the value you're requesting, and a written explanation with your comps attached.

Step 5: Submit before the deadline, then attend or waive the hearing. Most Kane County hearings are informal. Show up in person or submit in writing. In-person lets you answer questions on the spot, but a well-documented written packet usually holds up just as well.

If you want a structured way to organize comps and write your argument, the TaxFightBack DIY appeal kit walks each step with templates built around Illinois Board of Review standards, so you keep 100% of anything you win.

One honest note on odds. Illinois PTAB data shows roughly 60 to 70% of residential appeals get at least some reduction when the owner brings comparable sales evidence ^[7]. Kane County doesn't publish an aggregate Board of Review win rate, so I won't pretend to one. What I'll say is that two or three strong comps move the needle far more often than not.

How do I pay Kane County property taxes, and what happens if I miss a payment?

Kane County gives you several ways to pay ^[3]. Online through the Treasurer, by mail, or in person.

Online payment runs through the Kane County Treasurer's website. E-check is usually free. Credit card carries a service fee around 2.35%, charged by the payment processor, not the county. You can also mail a check or walk one into the Treasurer's office. For a wider look at online options across counties, see our guide to online tax payment for property.

Miss the June first installment or the September second installment and interest runs at 1.5% per month on the unpaid balance under 35 ILCS 200/21-15 ^[4]. That's 18% a year. After two years of delinquency, the county can offer the property at a tax sale, where an investor buys the lien and tacks on redemption interest ^[4].

If your mortgage servicer pays taxes from escrow, a late payment is their mistake to fix, but your credit and your property carry the risk if they drag their feet. Suspect a missed payment? Check your bill status directly on the Kane County Treasurer's site instead of trusting the servicer's word.

Kane County also runs a tax deferral program for qualifying seniors, letting them push payment until the property sells, under the Illinois Senior Citizens Real Estate Tax Deferral Act ^[4]. Income limits and deadlines apply. The Supervisor of Assessments office has the details.

How does Kane County compare to other Illinois counties on property taxes?

Kane County is reliably one of the five highest-property-tax counties in Illinois, and Illinois itself is one of the highest-tax states in the country ^[5].

Here is where Kane County lands against its Illinois neighbors and a few out-of-state counties people keep asking about:

County	State	Median Effective Rate (approx.)	Median Annual Tax
Kane County	IL	~2.7%	~$7,000+
DuPage County	IL	~2.1%	~$6,400
Cook County	IL	~1.9%	~$4,500
McHenry County	IL	~2.5%	~$5,800
Lake County	IL	~2.8%	~$7,500
Sedgwick County	KS	~1.4%	~$2,200

Sedgwick County, Kansas (home of Wichita) runs at roughly half Kane County's effective rate. That isn't a knock on Kane County's services, which plenty of residents value. It just shows why the tax burden here feels sharp next to peers elsewhere.

Stack Kane County against Collin County, Texas (effective rate near 1.8 to 2.0%, but no state income tax) or Santa Clara County, California (capped near 1.1 to 1.2% by Proposition 13) and the contrast gets starker. Illinois has no Prop 13 equivalent, so assessed values can climb with the market with no constitutional cap on how fast.

The Illinois General Assembly floats property tax reform every few years. As of mid-2025, no major structural change has passed ^[5].

What do I do after the Board of Review rules on my appeal?

If the Board of Review cuts your assessment, good. The new value feeds your next tax bill. You don't get a refund check for prior years. The reduction applies going forward from the year you appealed.

If the Board denies you or hands back less than you asked for, you have two paths.

The Illinois Property Tax Appeal Board (PTAB) is the first. It's a state administrative body that reviews Board of Review decisions de novo, meaning it looks at the evidence fresh rather than only checking for a procedural slip ^[7]. The residential filing fee is $10.50. You get 30 days from the date the Board of Review decision is mailed to file. PTAB is slow, often 12 to 24 months to a final decision, but it costs almost nothing to run yourself.

For more on the sequence after your first appeal, our piece on the steps that follow a property tax appeal covers PTAB filing, bill adjustments, and handling partial-year refunds if you eventually win a multi-year case.

Circuit court is the other path, but attorney fees usually start at $2,000 to $5,000 for a residential case, which rarely pencils out unless the disputed amount is large or the property is commercial. Most homeowners are better off with PTAB.

Worth knowing: a PTAB win for one tax year does not lock that lower value in forever. The assessor reassesses every four years and can push it back up. You may have to appeal again in the next quadrennial cycle.

Does Kane County have a property tax freeze or relief program for seniors?

Yes. The Senior Citizens Assessment Freeze is the main relief tool, and it's genuinely strong if you qualify.

Here is how it works in Kane County. Once you turn 65 and your total household income is $65,000 or less for the prior year, you can apply to freeze your EAV at its current level ^[4]. From then on, even if your home appreciates and the assessor would otherwise bump your EAV, the freeze holds it at the base year. You still pay tax on that frozen EAV. You just don't pay on the appreciation.

Reapply every year by July 1. Miss it and you lose that year's freeze. The application goes to the Kane County Supervisor of Assessments ^[1].

The $65,000 threshold counts most household income: wages, Social Security, pension distributions, rental income, interest. It does not subtract medical expenses, which trips up a lot of people. If your income sits near the line, pull last year's returns and total every source before assuming you're under.

Kane County also takes part in the Illinois Circuit Breaker program, run by the state, which hands an extra grant to qualifying low-income seniors and disabled residents. That program is separate from the exemptions above, and you apply through the Illinois Department of Revenue ^[2].

Own property in another high-tax county too? Our comparison with Miami-Dade property taxes is worth a look, since Florida's senior exemptions work nothing like Illinois's freeze model.

Where do I find my Kane County property tax bill, parcel information, and payment history?

Everything you need lives across three offices. Knowing which one handles what saves real frustration.

The Kane County Treasurer handles billing, payment, and payment history. Its website has an online lookup by parcel index number (PIN) or address, showing your current bill, installment amounts, due dates, and past payments ^[3]. Need a duplicate bill? Print one there.

The Kane County Supervisor of Assessments handles assessed value, exemptions, and property record cards ^[1]. Its online search lets you pull any parcel in the county, see current and prior-year assessed values, check which exemptions are applied, and view sale history.

Your PIN is the key that ties both systems together. It's a 14-digit number on your tax bill. No recent bill on hand? Search by address on either office's site.

The Kane County Clerk keeps the official tax rate records, the equalization factor, and levy history for each taxing district ^[9]. If you want to know why your rate moved from last year to this year, the Clerk's office is where that answer lives.

All three offices sit in Geneva, Illinois, the county seat. Hours and phone numbers are on each office's website. The Supervisor of Assessments line is (630) 208-3818 as of this writing, though I'd verify it on the site before you drive over ^[1].

Frequently asked questions

When are Kane County property taxes due in 2025?

Kane County taxes for the 2024 tax year (billed in 2025) come in two installments. The first is typically due in early June and equals 55% of the prior year's total. The second is due in early September. The Kane County Treasurer publishes exact dates each spring. Late payments accrue interest at 1.5% per month under 35 ILCS 200/21-15.

What is the Kane County property tax appeal deadline for 2025?

The deadline to file with the Kane County Board of Review varies by township, since each township publishes its assessed value list separately and that triggers a 30-day appeal window. Most townships open their windows between August and October. Check the Board of Review website in late July for your township's closing date. Miss it and you wait until next year.

How much can I save by appealing my Kane County property tax?

It depends on how overassessed you are. A 10% EAV cut on a home with a $150,000 EAV saves about $1,500 a year at a $10 per $100 rate. Illinois PTAB data suggests roughly 60 to 70% of residential appeals backed by comparable sales get at least some reduction. There's no filing fee at the Board of Review level, so the only real cost of trying is your time.

Does Kane County have a senior property tax freeze?

Yes. The Senior Citizens Assessment Freeze locks your Equalized Assessed Value at its current level once you're 65 or older with total household income of $65,000 or less. Apply annually by July 1 through the Kane County Supervisor of Assessments. If values rise, your EAV stays frozen, capping future increases. Miss the annual reapplication and you forfeit that year's freeze.

How do I find my Kane County parcel index number (PIN)?

Your PIN is printed on your Kane County tax bill. No recent bill? Search by address on the Kane County Supervisor of Assessments website or the Treasurer's online payment portal. The PIN is a 14-digit number that ties your property together across every county system, including assessments, exemptions, and payment history.

What is the General Homestead Exemption in Kane County and how do I apply?

The General Homestead Exemption cuts your Equalized Assessed Value by up to $6,000, trimming your annual bill by roughly $600 at a $10 per $100 EAV rate. It applies to owner-occupied primary residences. Apply once through the Kane County Supervisor of Assessments, typically by March 1, and it renews automatically. Buyers who purchase mid-year often miss it and pay an un-exempted bill for their first year.

Can I appeal my Kane County property taxes without a lawyer or contingency firm?

Absolutely. The Kane County Board of Review is built for self-representation. You need your property record card, three to six comparable sales, and the complaint form from the Board's website. Filing is free. Lose there and you can go to the Illinois PTAB for a $10.50 fee, still no attorney required. Contingency firms take 30 to 50% of savings. A DIY appeal keeps all of it.

What evidence do I need to appeal my Kane County property tax assessment?

The strongest evidence is recent comparable sales: homes close in size, age, style, and condition that sold for prices implying a lower market value than your assessment. Sales from the 12 to 18 months before January 1 of the tax year carry the most weight. A licensed appraisal works too. Errors on your property record card (wrong square footage, wrong bedroom count) are a separate and often easier basis for a cut.

How often does Kane County reassess property values?

Kane County townships reassess on a four-year (quadrennial) cycle. Each township runs its own schedule, so not every property reassesses in the same year. Find your township's reassessment year through the Kane County Supervisor of Assessments. Quadrennial years produce bigger value swings and more appeals than off years, since the assessor updates the entire property roll rather than making small tweaks.

What happens if I don't pay my Kane County property taxes?

Unpaid Kane County taxes accrue interest at 1.5% per month (18% a year) under 35 ILCS 200/21-15. After two years of delinquency, the county can sell the tax lien at a tax sale, where a buyer pays your back taxes and charges you redemption interest, often 18 to 36% a year, to reclaim your property. Keep failing to redeem and you can lose the property outright.

How do I check if my Kane County property tax exemptions are applied correctly?

Look up your parcel on the Kane County Supervisor of Assessments website. The property detail page shows which exemptions are active and the EAV reduction each one gives. Think you qualify for one that isn't showing? Contact the Supervisor of Assessments. Missing exemptions from prior years can sometimes be fixed retroactively, though Illinois generally limits corrections to the current year and one prior year.

How does Kane County property tax compare to Sedgwick County, Kansas?

Kane County's median effective rate is about 2.7%, producing median bills over $7,000 a year. Sedgwick County, Kansas (Wichita area) runs near 1.4% with a median bill around $2,200. The gap comes mostly from Illinois leaning hard on property taxes to fund schools, with no Prop 13-style cap on assessed value growth, versus Kansas's lower levy structure and different school funding mix.

Can I appeal Kane County property taxes if I just bought the property?

Yes, and new owners often have a strong case if the purchase price sits meaningfully below the assessor's implied market value. Your arms-length sale price is valid evidence. Illinois assessors sometimes argue a single sale is only one data point, so back it up with nearby comps. And file for the General Homestead Exemption right away if you'll live there as your primary residence.

Sources

1. Kane County Supervisor of Assessments, Official Website: Kane County has sixteen townships with elected assessors; exemption applications and property record cards are handled by the Supervisor of Assessments; contact number and office procedures.
2. Illinois Department of Revenue, Official Website: Illinois uses an equalization factor (multiplier) calculated by IDOR to bring county assessments in line with statewide market values; Circuit Breaker program administration.
3. Kane County Treasurer, Official Website: Kane County issues two-installment tax bills (June and September); online payment options; 600+ tax code areas in the county; tax code rate files published annually.
4. Illinois Compiled Statutes, 35 ILCS 200 (Property Tax Code): Assessment at 33.33% of fair cash value (35 ILCS 200/9-145); late payment interest at 1.5% per month (35 ILCS 200/21-15); Homestead Improvement Exemption (35 ILCS 200/15-180); Senior Freeze income threshold of $65,000; veterans exemptions (35 ILCS 200/15-165).
5. Tax Foundation, Property Taxes by State and County: Illinois ranked among the highest states for effective property tax rates in 2023 data; Kane County effective residential rate approximately 2.6-2.8% of market value; no Illinois equivalent to California's Proposition 13.
6. Kane County Board of Review, Official Website: Board of Review complaint period opens 30 days after township publication of assessed value lists; township-by-township appeal schedules posted annually; complaint form and procedures for residential appeals.
7. Illinois Property Tax Appeal Board (PTAB), Official Website: PTAB accepts appeals within 30 days of Board of Review decision mailing; residential filing fee is $10.50; PTAB reviews evidence de novo; approximately 60-70% of residential appeals with comparable sales evidence result in reduction.
8. Lincoln Institute of Land Policy, Significant Features of the Property Tax: Illinois property tax structure, equalization process, and comparison of effective rates across counties including Kane, DuPage, Cook, McHenry, and Lake counties.
9. Kane County Clerk, Official Website: Kane County Clerk maintains official tax rate records, equalization factor history, and levy data for each taxing district; final rates published each spring.
10. U.S. Census Bureau, American Community Survey: Kane County median real estate taxes paid and median home values used to calculate effective property tax rates in comparison tables.