Illinois Property Tax Appeal Board: How to Lower Your Property Taxes in Illinois
If your Illinois assessment notice arrived and the number looks too high, you have the right to challenge it — without hiring anyone. Illinois gives homeowners two distinct paths: a local appeal to your county's Board of Review, and if that doesn't go your way, an appeal to the Illinois Property Tax Appeal Board/PTAB, the state-level body that reviews residential assessments. This guide walks you through both.
Step 1 — Start With Your County Board of Review
Every Illinois county has a Board of Review that accepts complaints about over-assessed property values. This is your first and often fastest option. The process typically looks like this:
- Check your assessment notice for the appeal deadline — it varies by county and township and changes each year. Missing it means waiting until the next assessment cycle.
- Get your county's complaint form from the Board of Review website or office. Cook County's form differs from downstate counties.
- Gather comparable sales (comps) — recent sales of similar homes nearby that support a lower market value. Three to five solid comps are usually enough.
- Submit the form and your evidence by the deadline. Many counties accept filings online, by mail, or in person.
- Attend a hearing if one is scheduled, or accept the board's written decision.
Always verify the exact deadline and form requirements directly with your county Board of Review — rules differ across Illinois's 102 counties and can change annually.
Step 2 — Escalate to PTAB if the Board of Review Denies You
If the Board of Review reduces your assessment but not enough — or denies your complaint entirely — you can file a petition with PTAB. A few things to know before you do:
- PTAB has its own petition form and filing deadline, which is separate from the Board of Review deadline. The clock typically starts after the Board of Review issues its final decision.
- PTAB hearings are more formal than local board hearings. You'll present evidence — comps, an appraisal, or a uniformity argument — to a hearing officer.
- A uniformity appeal argues your assessment is higher than comparable properties nearby, even if it isn't above market value — a common and effective argument in Illinois. Other states handle this differently; see how New Jersey property tax appeals work for comparison.
- PTAB decisions can take months to over a year. If you win, the reduction is retroactive to the tax year in question.
Check PTAB's official site (ptab.illinois.gov) for current petition forms, instructions, and filing windows. Do not rely on third-party summaries for deadlines — confirm directly with the agency.
What Evidence Actually Works in Illinois
Illinois boards respond to two main arguments: overvaluation (your home is assessed above its market value) and uniformity (your home is assessed higher than similar nearby properties). Comparable sales data supports both.
Strong evidence includes recent arm's-length sales of homes with similar square footage, age, style, and condition within your neighborhood or township. A licensed appraisal carries the most weight at PTAB, though comps alone often succeed at the Board of Review level. Photographs of property condition, repair estimates, or a recent purchase price below the assessed value can also help.
Don't Overlook Exemptions Before You Appeal
Illinois offers several exemptions that reduce your assessed value before the tax rate applies — homestead, senior citizen homestead, senior freeze, veteran, and disability exemptions. If you're not claiming every exemption you qualify for, contact your county assessor — it's the fastest way to lower your bill without a formal appeal.
Is It Worth Appealing on Your Own?
The Board of Review process costs nothing to file and can often be completed without a hearing. Many homeowners who bring three to five solid comparable sales walk away with a reduction. PTAB is more involved but still accessible without an attorney — PTAB publishes plain-language guides for self-represented petitioners.
Appeal companies and tax attorneys operate in Illinois on a contingency fee — typically a percentage of your first-year savings. That may be worth it for a complex PTAB case or a substantially over-assessed property. For a straightforward overvaluation with solid comps, the DIY route at the Board of Review is very achievable. A reduction is never guaranteed regardless of who files.