When Do Property Tax Bills Come Out in Illinois? Key Dates and Deadlines
TL;DR
Illinois property tax timing varies by county and township. Assessment notices arrive at different times depending on your township's reassessment schedule. In Cook County, reassessment notices trigger a 30-day appeal window to the Assessor, followed by the Board of Review. Outside Cook County, appeal to the county Board of Review within 30 days of publication. Tax bills typically arrive in the spring and summer, with payment due in two installments. Cook County homeowners should watch the Assessor's website for their township's reassessment schedule.
Illinois Property Tax Calendar
| When | What Happens | Your Action |
|---|---|---|
| January 1 | Assessment date | Exemption qualification date |
| Varies by township | Assessment notices mailed | Review immediately |
| 30 days after publication | Appeal deadline | File with Assessor or Board of Review |
| Spring (varies) | First installment tax bill | Pay (typically 55% of prior year's bill) |
| Summer-Fall (varies) | Second installment tax bill | Pay remaining balance |
Cook County vs. Rest of Illinois
Illinois property taxes are complicated by the fact that Cook County (Chicago) operates under a different system than the rest of the state.
Cook County
Cook County reassesses on a triennial (3-year) cycle. Different townships are reassessed in different years. The process includes:
- Assessor's reassessment: New values published by township. You have 30 days to appeal to the Assessor's office.
- Board of Review: After the Assessor's review period, the Board of Review opens its own appeal window (typically 30 days). This is a second chance if the Assessor did not reduce your value.
Cook County uses different assessment levels for different property types:
- Residential: 10% of market value
- Commercial: 25% of market value
- Industrial: 25% of market value
To find the implied market value of your Cook County home, multiply the assessed value by 10.
Rest of Illinois
Outside Cook County, properties are assessed at 33.33% of market value. Assessment notices are published in the local newspaper, and you have 30 days from publication to file with the county Board of Review.
Some counties outside Cook County also have a triennial cycle, while others assess annually. Check with your county assessor.
When Tax Bills Arrive
Illinois tax bills are notoriously late and unpredictable in timing, especially in Cook County:
- First installment: Usually mailed in January-March. It is 55% of the prior year's total tax bill. Due about 30 days after mailing.
- Second installment: Usually mailed in the summer or fall. This reflects the final tax calculation with updated assessments and rates. Due about 30 days after mailing.
Cook County second installment bills have been notoriously delayed in some years, sometimes arriving in October or November instead of the typical July-August window.
Illinois Exemptions
Illinois offers several valuable exemptions:
| Exemption | Reduction | Eligibility |
|---|---|---|
| General Homestead | Up to $10,000 off EAV ($10,000 in Cook County) | Owner-occupied primary residence |
| Senior Homestead | Up to $8,000 off EAV | Age 65+, owner-occupied |
| Senior Freeze | Freezes EAV at base year level | Age 65+, income under limit |
| Disabled Persons | $2,000 off EAV | Homeowners with qualifying disability |
| Disabled Veterans | Up to $100,000 off EAV | Veterans with service-connected disability |
EAV = Equalized Assessed Value. These exemptions must be applied for and may need annual renewal. Full Illinois exemptions guide.
How to Appeal in Illinois
Cook County Process
- File with the Cook County Assessor during the township's open appeal window (30 days after reassessment values are published)
- If unsuccessful, file with the Cook County Board of Review during their open window
- If unsuccessful, appeal to the Illinois Property Tax Appeal Board (PTAB) or Circuit Court
Outside Cook County
- File with the county Board of Review within 30 days of assessment publication
- If unsuccessful, appeal to PTAB or Circuit Court
Frequently Asked Questions
Why are Illinois property taxes so high?
Illinois has one of the highest effective property tax rates in the nation (averaging over 2.0%). This is driven by heavy reliance on property taxes for school funding and the state's large number of overlapping taxing districts. Some areas have over a dozen taxing bodies stacking their rates.
When is my township's reassessment year (Cook County)?
Cook County rotates reassessments: City of Chicago, North/Northwest suburbs, and South/Southwest suburbs each on a 3-year cycle. Check the Cook County Assessor's website for your township's schedule.
What is the equalization factor (multiplier)?
The Illinois Department of Revenue applies an equalization factor (or "multiplier") to Cook County assessments to bring them in line with the state's 33.33% standard. The multiplier changes annually. When calculating your tax, the assessed value is multiplied by this factor before tax rates are applied.
Illinois Property Taxes Are Among the Highest in the Country
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