Cook County mailed its Tax Year 2025 second-installment property tax bills on September 1, 2026, two months later than usual, and they were due October 1. For Inverness, these were the first bills to reflect the Cook County Assessor's 2025 reassessment of the northern suburbs. They also carry two numbers that look like they contradict each other. In the Cook County Clerk's 2025 Tax Rate Report, Inverness's average composite tax rate fell from 9.230250 in 2024 to 7.856283 in 2025, a 14.89% drop. Over the same period, the Cook County Treasurer's Tax Year 2025 analysis found that the median homeowner bill in Inverness rose 12.2%.
Both numbers are accurate. The tax rate is the result of the calculation, so on its own it says little about what a bill will be. If you are weighing a house in Inverness, the numbers that matter are the date on the tax history, the township the parcel sits in, and what voters in that school district approved.
Check the Date on the Tax History First
Because the bills arrived late, any Inverness tax figure dated before September 2026 comes from the Tax Year 2024 bill, which was calculated before the 2025 reassessment. That older bill does not include the jump in assessed values or the new school bond levy described below. A tax history that looked current in August may be a year behind by November.
The new bill also affects the next one. The Treasurer's office says the first-installment bill equals 55% of the previous year's total tax and is usually due March 1. If the usual schedule holds, the Tax Year 2026 first installment, due around March 1, 2027, will be calculated from the Tax Year 2025 bills that went out this fall. The Treasurer's due-date page lists the official deadlines once the county sets them.
Why the Rate Fell
A tax rate comes out of a division. Each taxing body sets a dollar levy, and the rate is that levy spread across the total assessed value of the property it taxes. When assessed values rise quickly, the same levy is spread over a larger base and the rate goes down, even if nobody's bill does.
That is what happened in Inverness for Tax Year 2025:
| Measure, Inverness | 2024 | 2025 | Change |
|---|---|---|---|
| Median residential assessed value | $53,459 | $69,320 | +29.67% |
| Average composite tax rate per PIN | 9.230250 | 7.856283 | -14.89% |
| Village of Inverness rate | 0.463867 | 0.371978 | -19.81% |
| Median homeowner tax bill | n/a | n/a | +12.2% |
The 29.67% rise in median assessed value covers 3,056 residential properties. It put Inverness among the largest increases in the Treasurer's northern assessment region, alongside Barrington Hills at 32.01% and South Barrington at 30.26%. The rates for nearly every body listed in the Clerk's Inverness table fell, including Cook County, the Forest Preserve District of Cook County, and the corporate funds of both Barrington and Palatine townships. The state multiplier did not drive any of this. Cook County's final 2025 equalization factor was 3.0300, compared with 3.0355 in 2024, and the Clerk's office described its effect as minimal.
A falling rate on a rising base can still produce a larger bill. In Inverness it did, for two reasons.
Where the Increase Came From
The first reason was a vote. On November 5, 2024, voters in Barrington Unit School District 220 approved a $64 million bond referendum. The district estimated the cost at an additional $236 per year for the average household, based on a $500,000 market-value home, for 20 years. The Treasurer attributes the median bill increases in the Cook County portions of four District 220 communities partly to that bond: South Barrington at 16.4%, Barrington Hills at 15%, Inverness at 12.2% and Barrington at 11.5%. The Daily Herald's coverage of the report listed the same four figures.
The second reason was which kinds of property gained value. The Treasurer notes that in these suburbs home values rose faster than business values. When homes make up a larger share of the total assessed value, homeowners pay a larger share of each levy, whatever the rate does. Across the north and northwest suburbs in Tax Year 2025, residential property taxes rose 9.9% while taxes on business property rose 0.2%. The median homeowner bill in the region rose 6.7% to $8,007, and the median commercial bill fell 3.5% to $28,253. In the Treasurer's figures, residential property's share of the region's total tax burden rose by about two percentage points.
The appeals process also shaped the result. The Assessor's office reported that across 13 north and northwest townships, residential property's share of assessed value rose from 66% before the 2025 cycle to 68% after Board of Review appeals. Board decisions reduced commercial assessed values by 14% in 2025, compared with 20% in 2022. The burden still moved toward homeowners this cycle, just more slowly than in the last one.
Two Townships Share One Village Name
Inverness's 7.856283 rate is an average per parcel. The Clerk's report says an individual rate may be higher or lower depending on the combination of taxing districts serving a property. In Inverness, that combination depends mainly on which township a parcel is in, and the Clerk's table lists levies from both Barrington Township and Palatine Township. The village's own budget documents describe the split this way:
- Barrington Township parcels are served by Barrington Unit School District 220, the district whose 2024 bond appears on this year's bills.
- Palatine Township parcels are served by School District 15, Township High School District 211, Palatine Park District and Harper College 512.
So the referendum the Treasurer connects to Inverness's 12.2% applies to parcels in the District 220 tax codes, and Palatine Township parcels pay a different set of school and park levies. Two Inverness listings with similar prices can have different tax bills because their parcels sit in different taxing districts. A seller's tax history describes that parcel only.
Values on each side have also moved from different starting points. The Assessor's estimates for single-family homes in Barrington Township rose from a median of $633,000 in 2022 to $803,000 in 2025. In Palatine Township, the single-family median rose from $350,000 to $431,000 over the same three years. These figures cover the whole townships, not just Inverness, and they are Assessor estimates rather than bill changes. They do show that the two halves of the village were reassessed against very different township-wide medians.
What the Bond Is Paying For
The District 220 bond funds safety and security work across the district, a new Barrington High School community auditorium, and upgrades to STEAM and instructional spaces, including science labs, fine-arts spaces, career pathways, mechanical systems, and windows, doors and flooring. The district's Transform220 page says, in its June 2026 update, that ground has been broken on the auditorium. The page lists the auditorium and the window, door and flooring work as under construction, with other projects still in design. The district describes the full design, bidding and construction sequence as taking about four years.
For a buyer, the construction timeline and the tax cost run on different schedules. The district's own estimate spreads the bond's cost over 20 years, so for District 220 parcels in Inverness the bond payments that started showing up this fall continue long after the auditorium opens.
Quick Answers
Did Inverness taxes go down because the rate dropped? No. The average composite rate fell 14.89% for Tax Year 2025, while the median homeowner bill rose 12.2%, because assessed values grew faster than the rate fell.
Does every Inverness home pay the District 220 bond? The bond is a District 220 levy, so it applies to parcels in District 220 tax codes, which are on the Barrington Township side. Palatine Township parcels are taxed by School District 15 and Township High School District 211.
When will the next Cook County bill arrive? The first installment is 55% of the prior year's total tax and is usually due March 1, so the next one is expected in early 2027 and will be based on the Tax Year 2025 bill.
This post is general information about how Cook County bills were calculated. It is not legal, tax or financial advice, so confirm your own parcel's situation with a tax professional or the county offices linked above.
When we prepare a valuation in Inverness, we start with the parcel's township, its taxing districts and its latest bill, because those affect a buyer's monthly cost almost as much as the price does. To see how your home's Tax Year 2025 bill fits into its market value, Morrison Home Team can walk you through it. Request Your Free Home Valuation.