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How do I appeal my property tax assessment?

Township Assessor / County Assessor (informal review) / County Board of Review (formal county appeal) / Illinois Property Tax Appeal Board - PTAB (state appeal) / Circuit Court (judicial appeal)
Step by Step

How to do it

  1. Review assessment notice (Cook County reassesses on a 3-year township cycle; even in non-reassessment years, you can appeal)
  2. Appeal to Cook County Assessor first (when your township opens - varies by township; typically 30-day window); Cook County Assessor: cookcountyassessor.com
  3. If unsatisfied: appeal to Cook County Board of Review (separate 30-day window after Assessor appeal; township-specific schedule August-December; track at cookcountyboardofreview.com)
  4. If still unsatisfied: appeal to PTAB within 30 days of Board of Review decision
  5. ALL OTHER COUNTIES (102-county process, minus Cook):
  6. Contact your Township Assessor or County Supervisor of Assessments informally first
  7. FILE with the County Board of Review within 30 days of the publication/mailing of your assessment notice (deadline varies by county; call Board of Review or Supervisor of Assessments for exact annual deadline)
  8. Gather evidence: comparable sales, independent appraisal, photos of property condition, factual errors
  9. Attend Board of Review hearing; present evidence
  10. If unsatisfied: appeal to PTAB within 30 days of Board of Review's written decision
  11. If still unsatisfied: appeal to Circuit Court
  12. PTAB APPEAL (any county):
  13. - File within 30 days of County Board of Review written decision
  14. - File by mail to PTAB, Springfield - fax/email NOT accepted
  15. - Attorney-represented appellants must file through PTAB eFiling portal
Details

What you need to know

Required Docs
  • Completed appeal form (county Board of Review form; PTAB form for state appeal)
  • Supporting evidence: comparable sales, independent appraisal, photos, error documentation
  • Property PIN and assessment notice
Fee
County Board of Review: no fee in most counties; PTAB: no filing fee for most residential properties; Circuit Court: filing fees apply COUNTY BOARD DEADLINE: 30 days from assessment notice publication - verify annually with your county PTAB DEADLINE: 30 days from Board of Review written decision - hard deadline; late filings rejected ONLINE OPTION: Cook County Board of Review: online filing available; PTAB: eFiling for attorney-represented cases; other counties: check individual Board of Review websites WHERE TO GO: Township Assessor (informal); County Board of Review (county appeal); PTAB - ptab.illinois.gov (state appeal, Springfield)
Online Option
Cook County Board of Review: online filing available; PTAB: eFiling for attorney-represented cases; other counties: check individual Board of Review websites
Where to Go
Township Assessor (informal); County Board of Review (county appeal); PTAB - ptab.illinois.gov (state appeal, Springfield)
County-specific variations apply

Cook County has the most complex process with two appeal opportunities (Assessor + Board of Review) and township-specific deadlines that run August-December. The other 101 counties each have their own Board of Review with different filing deadlines, procedures, and evidence requirements. Some DuPage townships publish in October; others vary. ALWAYS call your specific county's Board of Review for current year deadlines.

Illinois Notes

Important state-specific details

  • Illinois EAV = 33.33% of market value (equalized); you are always challenging the underlying market value estimate.
  • Illinois PTAB (Property Tax Appeal Board): state-level quasi-judicial body with statewide jurisdiction; free for residential homeowners; ptab.illinois.gov.
  • KEY EXEMPTIONS often missed: Homeowner Exemption, Senior Citizen Homestead Exemption ($8,000 additional), Senior Freeze, Veterans Exemption - apply at County Assessor separately from appeal; these often reduce tax more than an assessment appeal.
  • 7% annual EAV cap (Cook County homestead property): if your EAV increased more than 7%, verify the cap is being applied.
  • Illinois appeals CAN be filed annually even in non-reassessment years.
  • PTAB multi-year backlog: some counties have 2-3 year PTAB backlogs; county Board of Review resolution is usually faster.
Official Source

State office contact

State Office
Illinois PTAB - ptab.illinois.gov | (217) 782-6076 | 160 N. LaSalle St., Chicago, IL 60601 (Chicago office) or Springfield; Cook County Board of Review: cookcountyboardofreview.com | (312) 443-5542