Property Tax Appeals in Illinois
How it works in Illinois
In Illinois, assessments are challenged county by county. Your county's Board of Review hears written complaints that a property is over- or under-assessed and can correct the assessment. If you disagree with the Board of Review's decision, the state's Property Tax Appeal Board is a further step. Cook County also lets owners appeal to the county Assessor's office first, before going to the Board of Review.
Deadline
A Board of Review complaint must be filed within 30 calendar days after your county publishes its assessment list, and a complaint sent by U.S. mail counts as filed on its postmark date (35 ILCS 200/16-55, read directly from the Illinois General Assembly's site). Each county publishes on its own schedule, and in Cook County each township does, so the calendar date differs by where you live.
Terminology
Illinois uses "appeal," and the Board of Review formally calls the filing a "complaint." It is filed with your county's Board of Review, not with the state.
- Cook County reassesses on a three-year cycle. The City of Chicago, the north and northwest suburbs, and the south and west suburbs each take a turn, so most Cook properties get a new value only once every three years.
- Only Cook County is covered with verified data so far. Other Illinois counties have their own Boards of Review and publication schedules, so check your own county's Board of Review for its dates.