Challenging a Property Tax Assessment: What Homeowners Should Know

Property taxes are one of the largest ongoing expenses for homeowners — yet many pay them without verifying the accuracy of their assessments. If your home’s assessed value is too high, you may be overpaying. Here’s how to review and challenge your property tax assessment effectively:

Steps to Review Your Property Tax Assessment

1. Understand How the Assessment Is Calculated

Assessments are often based on a percentage of your home’s market value — not the full value itself. Check how your local assessor determines the assessed value and confirm what percentage is used.

2. Verify Your Property Information

Ensure the assessor’s records are accurate:

• Square footage

• Number of bedrooms/bathrooms

• Finished basement status

• Applicable tax exemptions (e.g., owner-occupied, senior, disabled, veteran)

  
  

3. Compare to Similar Properties

Look up assessments of three to five comparable homes in your neighborhood to determine whether your property is in line.

4. File an Appeal if Needed

If your assessment appears inaccurate, file an appeal through your county’s Board of Review. You may also begin by contacting your local assessor’s office directly to address minor issues informally.

When to Consider Appealing

• Your home’s market value has declined, but the assessment hasn’t

• Property records show errors (wrong square footage, outdated details)

• Nearby similar homes are assessed significantly lower

• You paid less than the assessed value when purchasing your home

• Eligible exemptions aren’t applied to your tax bill

Know the Deadlines

Illinois homeowners typically have 30 days from the mailing date of their assessment notice to file an appeal. Each county sets its own timeline, so check your local assessor’s or Board of Review website for specific dates and forms.

Tip: Don’t wait! Missing the filing window could mean overpaying for another year.