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Updated 2025 Tax Year

LaSalle County
Property Tax Guide

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

10 Official Sources
8 min read
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Quick Facts
Tax Rate
Varies by location and taxing districts - rates differ significantly throughout LaSalle County based on local services
Exemptions
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Section 1

How Property Tax Works

LaSalle County, Illinois operates under a property tax system that funds essential local services including schools, municipal services, fire protection, libraries, and county operations. Property taxes are assessed at 33.33% of fair market value as of January 1, 2025, based on sales data from 2022-2024. The county's median assessment level is currently 30.29%.

Effective property tax rates vary significantly throughout LaSalle County depending on your specific location and the combination of taxing districts that serve your property. These districts can include school districts, municipalities, townships, fire protection districts, library districts, and other special service areas. Property owners should expect their actual tax rate to differ from county averages based on their specific taxing district combination.

Property taxes in LaSalle County are subject to the Property Tax Extension Limitation Law (PTELL), which limits annual tax increases. The county offers several tax credits and exemptions for eligible property owners, though most require annual application and are not automatically applied.

Section 2

What Makes Up Your Tax Bill

ComponentRateDescription
County GeneralVariesCounty operations and services
School DistrictsVariesElementary and high school districts
MunicipalVariesCity/village services (if applicable)
TownshipVariesTownship services and assessments
Fire ProtectionVariesFire district services (if applicable)
Library DistrictVariesPublic library funding (if applicable)
Park DistrictVariesRecreation services (if applicable)
Other Special DistrictsVariesAdditional local services

Note: These rates apply to the 2025 tax year and vary significantly by location within LaSalle County. Your property may be served by different combinations of these taxing districts. The total effective rate is the sum of all applicable district rates for your specific location. Contact the LaSalle County Clerk at 707 Etna Road, Ottawa, IL 61350 for your specific district combination and rates.

Section 3

When Are Property Taxes Due?

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

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 LaSalle County are additional tax bills issued when there are changes to property that weren't reflected in the regular assessment cycle. Common triggers include new construction, property improvements, ownership transfers that reveal unreported improvements, or corrections to assessment errors that result in underbilling.

Supplemental taxes are calculated by applying the current tax rate to the difference between the new assessed value and the original assessed value. For example, if you complete a $100,000 home addition mid-year, the supplemental tax would be calculated on the additional assessed value (33.33% of $100,000 = $33,330 additional assessed value) multiplied by your local tax rate.

The County Clerk's Office may issue supplemental bills throughout the year as these changes are identified and processed. Property owners receive separate bills for supplemental taxes, which have their own due dates typically 30 days from the bill date.

Example Calculation

Example 1: $300,000 Home

  • Market Value: $300,000
  • Assessed Value (33.33%): $99,990
  • Less: General Homestead Credit: -$10,000
  • Net Taxable Value: $89,990
  • Annual Tax (assuming 3.5% rate): $3,150
  • Monthly Escrow: $262

Example 2: $600,000 Home

  • Market Value: $600,000
  • Assessed Value (33.33%): $199,980
  • Less: General Homestead Credit: -$10,000
  • Net Taxable Value: $189,980
  • Annual Tax (assuming 3.5% rate): $6,649
  • Monthly Escrow: $554

Example 3: $1,000,000 Home

  • Market Value: $1,000,000
  • Assessed Value (33.33%): $333,300
  • Less: General Homestead Credit: -$10,000
  • Net Taxable Value: $323,300
  • Annual Tax (assuming 3.5% rate): $11,316
  • Monthly Escrow: $943

Note: Tax rates vary by location within LaSalle County. Credits shown require application and approval. Actual rates may differ significantly based on your specific taxing districts.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in LaSalle County require property tax escrow accounts for borrowers with less than 20% down payment. Your lender collects monthly payments equal to 1/12 of your estimated annual property tax bill plus insurance premiums. These funds are held in an escrow account and used to pay your tax bills when due.

Property taxes in LaSalle County are typically due in two installments: June 1 and August 1. However, if bills are mailed late, the first installment may be due 30 days after the bill date. Your lender monitors these due dates and pays from your escrow account. You should receive copies of all tax bills and payment confirmations.

Lenders must provide annual escrow account statements showing all deposits, payments, and account balances. If your property taxes increase significantly due to reassessment or rate changes, your lender may require higher monthly escrow payments or request a lump sum payment to cover any shortage. Property owners remain ultimately responsible for ensuring taxes are paid even when using escrow services.

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 LaSalle County for 2025? A: Property taxes are typically due June 1 and August 1. However, if bills are mailed late, the first installment becomes due 30 days after the bill date.

Q: What tax credits are available and do I need to apply? A: The General Homestead Exemption reduces assessed value by up to $10,000 and REQUIRES APPLICATION. The Senior Citizens Assessment Freeze is available for qualifying seniors with limited income. The Homestead Exemption for Persons with Disabilities provides a $2,000 reduction in assessed value. Most credits require annual application and are NOT automatic.

Q: How does the Homestead credit work? A: The Homestead credit is actually an exemption that reduces your property's assessed value by up to $10,000. You must apply for this benefit - it's not automatic. The property must be your principal residence.

Q: When can I appeal my assessment and what's the deadline? A: The deadline for ALL 2025 assessment appeals in LaSalle County is Monday, December 1, 2025. Contact the LaSalle County Assessor's office to begin the appeal process.

Q: What are the penalties for late payment? A: Late payments are subject to interest and penalties as specified in Illinois state law. Contact the LaSalle County Treasurer for current penalty rates and payment options.

Q: Can I pay my taxes online? A: Contact the LaSalle County Treasurer's office at 707 Etna Road, Ottawa, IL 61350 for current online payment options and accepted methods.

Q: Why did my taxes increase when property values in my area decreased? A: Property taxes can increase even when values decrease due to rate increases by taxing districts, changes in exemption eligibility, or shifts in the tax burden between properties.

Q: How do special district taxes affect my bill? A: Special districts (fire, library, park, etc.) each levy their own taxes. Your total bill includes all districts serving your property. Moving within the county can significantly change your total tax rate based on which districts serve your new location.

Verified Sources

Backed by 10 Official Government Sources

Every fact in this guide is sourced from official county, state, and federal documents.

01
ASSESSED VALUES FOR 2025 Valuation date (35 ILCS ...lasallecountyil.gov
02
County
Exemptions | LaSalle County, ILlasallecountyil.gov
03
Budget Status With YTD Historylasallecountyil.gov
04
County
Assessment Publications | LaSalle County, ILlasallecountyil.gov
05
County
LaSalle County Boardlasallecountyil.gov
06
Tax Doc
When do I have to pay my property taxes?tax.illinois.gov
07
Tax Doc
PTAX-343 Application for the Homestead Exemptionlasallecountyil.gov
08
County
Assessments | LaSalle County, ILlasallecountyil.gov
09
County
LASALLE COUNTY, ILLINOIS ANNUAL FINANCIAL REPORT ...lasallecountyil.gov
10
Self Insurance Trust AFR 11/2020lasallecountyil.gov
All sources verified as of 2025 Tax Year

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