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Updated 2025 Tax Year

Carroll County
Property Tax Guide

Everything you need to know about property taxes in Carroll County, IL. Rates, due dates, exemptions, and how it affects your monthly payment.

9 Official Sources
8 min read
Quick Facts
Tax Rate
Varies by district, typically 2.27% base rate plus overlapping district rates
1st Due
Jun 1
2nd Due
Sep 1
Exemptions
5+ Available
Section 1

How Property Tax Works

Carroll County, Illinois operates under a property tax system that serves as the primary funding mechanism for local government services, including schools, townships, municipalities, and county operations. Property taxes in Carroll County support essential services such as education, public safety, road maintenance, and various municipal services. The county follows Illinois state property tax laws, including the Property Tax Extension Limitation Law (PTELL), which limits annual tax increases.

The effective property tax rate in Carroll County varies significantly depending on your specific location within the county due to overlapping special taxing districts such as school districts, fire protection districts, library districts, and municipal boundaries. For tax year 2024, the county reported a tax rate of 0.24471% at the county level, but when combined with all local taxing districts, total effective rates typically range from 2% to 4% of assessed value. The county's total equalized assessed value (EAV) for 2024/2025 is estimated at $560 million, representing a 14% increase from the previous year.

Section 2

What Makes Up Your Tax Bill

ComponentRateDescription
County General0.24471%Basic county operations and services
School Districts1.5-2.5%Elementary and high school districts (varies by location)
Township0.1-0.3%Township road maintenance and services
Municipal0.2-0.8%City/village services (where applicable)
Fire Protection0.1-0.4%Fire protection districts
Library District0.05-0.15%Public library services
Other Special Districts0.05-0.3%Airport, drainage, park districts

Note: These rates apply to tax year 2024 (payable in 2025). Actual combined rates vary significantly by property location within Carroll County due to different combinations of overlapping taxing districts. Properties may be subject to some or all of these components depending on their specific location and the taxing districts that serve that area.

Section 3

When Are Property Taxes Due?

For the 2025/2026 tax year in Carroll County, property taxes are due in two installments:

First Installment
Jun 1
Delinquent after Dec 10
Second Installment
Sep 1
Delinquent after Apr 10
Pro tip: If you pay through mortgage escrow, your lender splits these payments across your monthly mortgage. If you pay directly, set calendar reminders to avoid late penalties.
Section 4

Supplemental Tax Bills

Supplemental property taxes in Carroll County are additional tax bills issued when there are changes to a property's assessment or ownership during the tax year. The most common triggers for supplemental taxes include new construction, property improvements, changes in property use, or corrections to the original assessment. Unlike the regular property tax bill, supplemental taxes are prorated based on the number of months remaining in the tax year when the change occurred.

For example, if you complete a $50,000 home addition in July that increases your assessed value by $16,667 (at Illinois' one-third assessment ratio), and your combined tax rate is 3%, you would owe a supplemental tax of approximately $250 for the remaining six months of that tax year ($16,667 × 0.03 × 6/12 months). Supplemental tax bills are typically issued within 30-60 days after the county assessor processes the change and are due within 30 days of the bill date.

Example Calculation

Example 1: $300,000 Home

  • Market Value: $300,000
  • Assessed Value (33.33%): $100,000
  • Homestead Exemption Applied: -$10,000
  • Net Taxable Assessed Value: $90,000
  • Tax Rate (estimated): 2.8%
  • Annual Tax: $2,520
  • Monthly Escrow: $210

Example 2: $600,000 Home

  • Market Value: $600,000
  • Assessed Value (33.33%): $200,000
  • Homestead Exemption Applied: -$10,000
  • Net Taxable Assessed Value: $190,000
  • Tax Rate (estimated): 3.1%
  • Annual Tax: $5,890
  • Monthly Escrow: $491

Example 3: $1,000,000 Home

  • Market Value: $1,000,000
  • Assessed Value (33.33%): $333,333
  • Homestead Exemption Applied: -$10,000
  • Net Taxable Assessed Value: $323,333
  • Tax Rate (estimated): 3.3%
  • Annual Tax: $10,670
  • Monthly Escrow: $889

Note: The Homestead Exemption requires annual application and is not automatically applied. Tax rates vary by specific location within the county.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Carroll County require borrowers to establish an escrow account to ensure property taxes are paid on time. Your lender collects monthly payments equal to your estimated annual property tax divided by 12, plus a cushion amount typically equal to two months of payments. The lender holds these funds in an escrow account and pays your property taxes directly to Carroll County when they become due.

Property taxes in Carroll County are due in two installments: the first installment is due by July 1st, and the second installment is due by December 1st each year. Your lender will typically pay each installment shortly before the due date. You should receive an annual escrow analysis from your lender showing the account activity and any adjustments needed for the coming year. If your property taxes increase significantly due to reassessment or new tax rates, your monthly escrow payment may be adjusted accordingly. Homeowners can verify that payments were made by checking with the Carroll County Treasurer's office or accessing their online payment portal.

How HonestCasa Helps
  • Understand whether your escrow is set correctly
  • See how rising taxes will change your monthly payment
  • Plan ahead instead of being surprised by "shortage" letters
Section 6

Frequently Asked Questions

Q: When are property taxes due in Carroll County for the current tax year? A: Property taxes for tax year 2024 are due in two installments: first installment by July 1, 2025, and second installment by December 1, 2025.

Q: What tax credits are available and do I need to apply for them? A: The primary tax benefit is the Homestead Exemption, which reduces your equalized assessed value by up to $10,000. This requires annual application and is NOT automatic. Additional credits include the Homestead Exemption for Persons with Disabilities (HEPD) providing a $2,000 EAV reduction, and the Senior Citizens Assessment Freeze for qualified low-income seniors.

Q: How does the Homestead Exemption work? A: The Homestead Exemption doesn't reduce your property's market value, but rather reduces the equalized assessed value used for tax calculation purposes. You must apply annually with the Chief County Assessment Officer by the county deadline to receive this benefit.

Q: How often are properties reassessed in Carroll County? A: Illinois law requires properties to be reassessed at least every four years, though Carroll County may conduct assessments more frequently. The county uses statistical analysis and market data to ensure assessments reflect current market values.

Q: What are the penalties for late property tax payments? A: Late payments are subject to interest charges and penalties. Interest begins accruing after the due date, and additional penalties may apply for significantly delinquent payments. Contact the Carroll County Treasurer's office for specific penalty rates.

Q: Can I pay my property taxes online? A: Yes, Carroll County accepts credit and debit card payments online during the tax collecting season. Check the Carroll County Treasurer's website for the online payment portal and any associated convenience fees.

Q: How do special taxing districts affect my tax bill? A: Your property may be located within multiple overlapping taxing districts (school, fire, library, etc.), each with its own tax rate. The combination of all applicable district rates determines your total effective tax rate, which is why rates vary throughout the county.

Q: How do I appeal my property assessment? A: Assessment appeals must be filed with the Carroll County Board of Review during their scheduled appeal period, typically in late summer or early fall. You'll need to provide evidence that your property's assessed value is higher than its fair market value.

Q: What happens if I don't receive my tax bill? A: Property owners are responsible for paying taxes even if they don't receive a bill. Contact the Carroll County Treasurer's office immediately if you haven't received your bill by the typical mailing dates to avoid late penalties.

Q: Are property improvements immediately taxable? A: New construction and improvements may result in supplemental tax bills prorated for the remainder of the current tax year. Major improvements are typically assessed when discovered or reported, which may trigger additional taxes for that year.

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