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Updated 2025 Tax Year

Iroquois County
Property Tax Guide

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

10 Official Sources
8 min read
Quick Facts
Tax Rate
Base county rate 0.06%, total effective rates typically 6-8% (varies by taxing districts)
1st Due
Jun 1
2nd Due
Sep 1
Exemptions
5+ Available
Section 1

How Property Tax Works

Iroquois County, Illinois operates under the state's property tax system to fund essential local services including schools, roads, public safety, and county operations. Property taxes in Illinois are calculated based on assessed value, which is determined by the County Assessor and represents a percentage of fair market value. The Property Tax Extension Limitation Law (PTELL) governs how much taxing bodies can increase their levies each year.

Property tax rates in Iroquois County vary significantly by location due to the overlay of multiple taxing districts including school districts, municipalities, townships, fire protection districts, and other special service areas. For the 2025 levy year, the base county rate is certified at 0.06%, but total effective rates typically range from 6% to 12% when all taxing districts are combined. Property owners should note that their specific tax rate depends on which taxing districts serve their property location, making rates unique to each parcel within the county.

Section 2

What Makes Up Your Tax Bill

ComponentRateDescription
County General0.06%Base Iroquois County operations and services
School DistrictsVariesElementary and high school districts (largest component)
MunicipalVariesCity/village services where applicable
TownshipVariesTownship road maintenance and general services
Fire ProtectionVariesFire and emergency services districts
Library DistrictsVariesPublic library operations
Park DistrictsVariesRecreation and park maintenance
Other Special DistrictsVariesDrainage, cemetery, and other special service areas

Rates shown are for Levy Year 2025 (taxes payable in 2026). Total effective rates typically range from 6-12% depending on the combination of taxing districts serving each property location. Contact the County Clerk for your specific district combination and total rate.

Section 3

When Are Property Taxes Due?

For the 2025/2026 tax year in Iroquois 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 taxes in Iroquois County are additional property tax assessments that occur when there are changes to a property's assessed value during the tax year. Common triggers include new construction completion, property improvements, ownership transfers that prompt reassessment, or corrections to previous assessments. These supplemental bills are calculated using the same tax rate that applies to the regular assessment but are prorated based on when the change occurred during the tax year.

For example, if a property owner completes a $100,000 home addition in March and the addition increases the assessed value by $33,333 (at Illinois' one-third assessment ratio), the supplemental tax would be calculated on this additional assessed value for the remaining 9 months of the tax year. With a total tax rate of 8%, this would result in a supplemental tax of approximately $2,000 ($33,333 × 0.08 × 9/12 months). Supplemental tax bills are typically issued within 60-90 days after the assessment change is processed and have separate due dates from regular property tax installments.

Example Calculation

Example 1: $300,000 Home

  • Market Value: $300,000
  • Assessed Value (33.33%): $100,000
  • Less Homeowner Exemption: -$10,000
  • Net Taxable Value: $90,000
  • Annual Tax (8% rate): $7,200
  • Monthly Escrow: $600

Example 2: $600,000 Home

  • Market Value: $600,000
  • Assessed Value (33.33%): $200,000
  • Less Homeowner Exemption: -$10,000
  • Less Senior Freeze (if applicable): -$5,000
  • Net Taxable Value: $185,000
  • Annual Tax (8% rate): $14,800
  • Monthly Escrow: $1,233

Example 3: $1,000,000 Home

  • Market Value: $1,000,000
  • Assessed Value (33.33%): $333,333
  • Less Homeowner Exemption: -$10,000
  • Net Taxable Value: $323,333
  • Annual Tax (9% rate): $29,100
  • Monthly Escrow: $2,425

Note: Exemptions shown require annual application and eligibility verification. Tax rates vary by specific taxing district combinations. Senior Freeze Exemption requires application and income qualification.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Iroquois County require property tax escrow accounts to ensure timely payment of property taxes. The lender collects 1/12 of the estimated annual property tax amount with each monthly mortgage payment and holds these funds in an escrow account. Property taxes in Iroquois County are typically paid in two installments - the first installment due in mid-July and the second installment due in mid-September, though exact dates may vary slightly each year.

Lenders typically pay property taxes directly to the County Treasurer when bills are issued. Property owners should verify that their lender has received and paid their tax bills by checking online through the County Treasurer's website or by contacting their lender directly. If escrow shortfalls occur due to assessment increases or rate changes, lenders will typically spread the shortage over 12 months in addition to the increased payment amount. Property owners have the right to request annual escrow account statements and can appeal excessive escrow cushions that exceed two months of payments.

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 Iroquois County? A: For the current fiscal year, the first installment is due by mid-July (approximately July 12th) and the second installment is due by mid-September (approximately September 12th). Late payments incur a 1.5% penalty after the due date.

Q: What tax credits are available and how do I apply? A: The Homeowner Exemption reduces assessed value by up to $10,000 and requires annual application to the County Assessor. The Senior Citizens Assessment Freeze caps assessment increases for qualifying seniors and requires application with income verification. The Homestead Exemption for Persons with Disabilities provides a $2,000 reduction in assessed value with proper application and documentation.

Q: How does the Homestead Exemption work? A: The Homestead Exemption does not reduce market value but rather caps annual assessment increases, typically to 7% or 10% depending on the specific exemption type. This credit requires filing an application with the County Assessor and must be renewed periodically. It limits how much your assessed value can increase year-over-year, not your total assessment amount.

Q: How often are properties reassessed? A: Illinois law requires reassessment every four years in most counties, though annual reviews may occur. Iroquois County follows the state schedule, with the most recent general reassessment determining current values. Property owners can appeal assessments within 30 days of notification.

Q: What happens if I pay my taxes late? A: Late payments incur a 1.5% penalty per month after the due date. If taxes remain unpaid, properties may be subject to tax sale procedures. Interest continues to accrue until full payment is received.

Q: Can I pay my property taxes online? A: Yes, Iroquois County typically offers online payment options through the County Treasurer's website. Payment methods usually include electronic check and credit card options, though credit card payments may incur processing fees.

Q: How do special district taxes affect my bill? A: Special districts like fire protection, library, park, and drainage districts add separate line items to your tax bill. Your property's location determines which special districts apply, making each property's total rate unique based on the services provided to that area.

Q: What if I disagree with my property assessment? A: Property owners can file an appeal with the Board of Review within 30 days of receiving their assessment notice. Appeals should include comparable sales data or evidence of assessment errors. The appeal process is free, though some property owners choose to hire professional representatives.

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