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Thornton Township property tax appeal 2026

Thornton Township homeowners can appeal their 2026 assessment with the Cook County Assessor until Monday, November 23, 2026. Filing is free and online, and you do not need a lawyer.

File by Nov 23 · Free to file · About 15 minutes

Nov 23Last day to file20 days left · Assessor
Opened Oct 8Closes

Key dates for Thornton Township

Every township gets two chances a year: the Assessor first, then the Board of Review.

  1. Done

    Assessor appeals open

    Thursday, October 8, 2026

    Assessment notices mailed

  2. Next

    Last day to file with the Assessor

    Monday, November 23, 2026

  3. Coming

    Board of Review appeals

    Dates not published yet

Updated November 3, 2026. Dates from the Cook County Assessor and Board of Review calendars.

Are you overpaying?

Free check from the county’s own records. About 10 seconds.

What the public records show

We checked 55,375 homes in Thornton Township against the county’s 2026 assessments and recorded sales. 18,658 (34%) are assessed higher than similar homes nearby or above what similar homes sold for, with a median estimated saving of about $637 a year.

Share of homes that may be assessed too high, by town

  • Calumet City33%3,476 of 10,690
  • Lansing33%2,791 of 8,466
  • Dolton31%2,486 of 7,936
  • South Holland33%2,601 of 7,868
  • Harvey46%3,419 of 7,476
  • Riverdale34%1,056 of 3,128
  • Homewood20%455 of 2,258
  • Markham40%549 of 1,365
  • Burnham21%270 of 1,271
  • Hazel Crest35%416 of 1,203

Estimates from public records, not a promise; the county decides every appeal.

Towns in Thornton Township

Calumet City, Dolton, South Holland, Lansing, Harvey, Riverdale, Homewood (part), Hazel Crest (part), Thornton, Burnham, Dixmoor, Phoenix

Some towns are split between townships. Your assessment notice names yours, and our free check sorts it for you.

How to file with the Cook County Assessor, step by step

For the window that is open now. Illustrations, not screenshots; the county’s site may look a little different.

  1. 1

    Find your PIN

    Your 14-digit property index number is on your assessment notice and your tax bill, and at the top of a Morganwell packet.

  2. 2

    Open the Assessor's appeal site

    Go to cookcountyassessoril.gov/online-appeals, sign in or create a free account, and start a residential appeal for your PIN by November 23, 2026.

  3. 3

    Choose the reason

    Lack of uniformity (similar homes are assessed lower), overvaluation (similar homes sold for less), or your own recent purchase price.

  4. 4

    Describe it and state your value

    Write a sentence or two, or paste the statement from your packet, and enter the fair market value you are asking for.

  5. 5

    Upload your evidence

    Upload your packet as a PDF. You can attach more documents after you submit, as long as your township is still open.

  6. 6

    Submit and save the confirmation

    You get an email confirming the filing and one with your docket number. The decision comes by mail. If it is not enough, you can appeal again at the Board of Review.

See every Assessor screen with pictures

After you file

  1. Step 1Assessor decidesUsually several weeks after the township's window closes. The result comes by mail.
  2. Step 2Board of ReviewNot lowered enough? Appeal again when the township opens there. You can file there even if you skipped the Assessor.
  3. Step 3State appeal boardStill disagree? You can go to the Illinois Property Tax Appeal Board within 30 days of the Board of Review's decision.

Thornton Township was last fully reassessed in 2026; the next full reassessment is in 2029.

Your evidence

Homes usually win on one of three grounds.

Lack of uniformityYour home is assessed at more per square foot than similar homes in the same neighborhood and class. Three to five comparable homes nearby make the case.
OvervaluationSimilar homes sold for less than the value the county gives yours. Recent arm's-length sales count; foreclosure auctions and bank sales do not.
Your own purchaseIf you bought recently for less than the county's value, your closing price is strong evidence. The Assessor asks about sales in the last two years, the Board of Review the last three, and you must disclose a sale in that time either way.

Condo owners: the strongest evidence is usually recent sales of other units in the same building.

What good evidence looks like

Similar homes, side by side, compared per square foot. Here the first home is assessed higher than its neighbors.

HomeAddressSq ftCounty valuePer sq ft
Your home1200 Example Ave1,450$312,000$215
Similar home1214 Example Ave1,420$268,000$189
Similar home1309 Sample St1,500$279,000$186
Similar home1122 Model Ct1,390$255,000$183

An illustration with made-up homes. Your packet lists the real comparable homes with their PINs, addresses and county values.

Thornton Township appeal questions

When is the Thornton Township property tax appeal deadline in 2026?

The Cook County Assessor accepts 2026 appeals for Thornton Township until Monday, November 23, 2026. The Board of Review opens its own window later in the year; it has not published the dates yet.

Which towns are in Thornton Township?

Calumet City, Dolton, South Holland, Lansing, Harvey, Riverdale, Thornton, Burnham, Dixmoor and Phoenix, plus parts of Homewood and Hazel Crest. Your assessment notice names your township.

Was Thornton Township reassessed in 2026?

Yes. The Cook County Assessor reassessed Thornton Township in 2026, so homeowners received new estimated market values. The next full reassessment is in 2029.

Does it cost anything to appeal?

No. Filing with the Cook County Assessor and with the Board of Review is free, and homeowners can file for themselves without a lawyer.

How do I know if my home is assessed too high?

Compare it with similar homes nearby: same neighborhood, class, size and age. If yours is assessed higher per square foot than most of them, or above what similar homes sold for, that is the evidence the county asks for. Morganwell's free check does this comparison from the county's own records.

Can I appeal at the Board of Review if I did not appeal with the Assessor?

Yes. The Board of Review accepts appeals whether or not you filed with the Assessor first.

How many Thornton Township homes may be assessed too high?

Morganwell checked 55,375 homes in Thornton Township against the county's 2026 assessments and recorded sales. 18,658 of them (34%) are assessed higher than similar homes nearby or above what similar homes sold for, with a median estimated saving of about $637 a year. These are estimates from public records, not a promise; the county decides.

Can condo owners appeal?

Yes. For a condominium unit the strongest evidence is usually recent sales of other units in the same building. Morganwell's free check covers condo units as well as houses.

Guides for other townships

Thornton Township on Morganwell

Morganwell is not a law firm and does not give legal or tax advice. You file your own appeal. Packets are compilations of public records, not appraisals. No outcome is guaranteed.