PropTaxCheckerCook County, IL

Thornton Township property tax appeal deadline: November 23, 2026

Is your Thornton Township home assessed higher than similar homes nearby? Check in a minute, then file yourself for free.

Free. No sign-up. Compares your home with the 5 to 10 most similar homes nearby, from the Assessor's own data.

2026 appeal windows

Assessor appeals are open until November 23, 2026. 17 days left

Dates copied from the Assessor's calendar and the Board's dates page on 2026-10-30. Confirm before filing. Add these dates to your calendar.

How Thornton homeowners did at the Board of Review (2025)

Residential parcels
59,494
Appealed to the Board
7,498 (13%)
Filed on their own
4,475 (60%)
Won a reduction, filing alone
46%
Won a reduction, with an attorney
37%
Average AV cut, filing alone
$818

County-wide, homeowners filing alone won 57.6% of residential appeals versus 38.9% for attorney-filed ones. Computed 2026-11-03 from the Board of Review's decision data (classes 200-299, "won" = Board value below the Assessor's certified value). Averages include appeals that got no change. An assessed-value cut of $1,000 is roughly $242 to $424 a year off a suburban bill.

What to do

  1. Run the free check above. It compares your assessed value per square foot with similar homes in your assessment neighborhood.
  2. If yours looks high, get the evidence kit from the result page: the comps in the Board's format, recent sales, and a statement to paste into the form.
  3. File online at the office whose window is open. Filing is free at both. You type the complaint yourself; only you or an Illinois attorney can file for your home.
  4. Leave an email on the result page and we'll remind you a week and three days before the deadline.

New to this? Read how to appeal, step by step.

Towns in Thornton Township

Calumet CityHarveyDoltonSouth HollandLansingRiverdaleHomewoodMarkhamHazel CrestBurnhamThorntonDixmoorPhoenixEast Hazel CrestPosenGlenwood