Townships, and why yours matters more than you think
The township is the unit of assessment, the unit of the reassessment cycle, and the unit of your deadline.
The township is the unit Illinois property assessment is organised around, and it decides more about your appeal than most owners realise — including when you can file.
What a township does
Outside Cook County, an elected township assessor values every property in the township. The county's Supervisor of Assessments then equalises between townships, applies exemptions and publishes the roll.
In Cook County, the County Assessor values everything centrally, but townships remain the organising unit for reassessment and for appeal deadlines.
The three things it determines
1. Your deadline
The 30-day appeal window runs from publication of your township's roll. Publication is staggered across months, so there is no single county deadline. This is the most common way people miss theirs — they hear a date from someone in another township.
2. Your reassessment year
Cook reassesses by triad, one third of townships each year. Elsewhere, quadrennial by township. Which year you are in determines whether your value was just rebuilt or is being carried forward.
3. Who you are compared against
Comparables should come from within your assessment jurisdiction. A property across a township line was valued by a different assessor, or in Cook by a different part of the model, and is a weaker comparable however similar the house.
Why success rates differ so much by township
Cook County's published decisions show appeal success rates varying four-fold in the same year — 30.6% in Jefferson Township against 7.6% in Palatine for tax year 2024.
| Township | 2024 success rate |
|---|---|
| Jefferson | 30.6% |
| Lake View | 30.5% |
| West Chicago | 22.1% |
| New Trier | 14.2% |
| Elk Grove | 10.1% |
| Palatine | 7.6% |
Some of that is where each township sat in the reassessment cycle. Some is how uniform the housing stock is — a township of near-identical post-war houses produces clean comparables, one of varied custom homes does not. And some is the mix of who files.
What to do with this
Find your township on your assessment notice, then find three things: your appeal deadline, your reassessment year, and your township's published success rate. The first is non-negotiable, the second tells you what argument is available, and the third tells you what base rate you are working against before you spend the evening.
Townships do other things too
Outside assessment, an Illinois township is a unit of local government with its own board, its own levy and its own line on your tax bill. It typically runs road maintenance outside municipal boundaries and general assistance, and in some places a good deal more.
That levy is usually a small share of the bill — schools dominate — but it is there, and it is decided at public meetings that almost nobody attends.
Chicago is organised the same way
People assume townships are a rural thing. The City of Chicago is divided into eight assessment townships — Hyde Park, Jefferson, Lake, Lake View, North Chicago, Rogers Park, South Chicago and West Chicago — and they are the units the reassessment cycle and the appeal calendar run on.
They are also large. Lake View alone decided 66,784 appeals for tax year 2024, more than most entire counties in the state.