Will County property tax appeal 2027: deadline, forms and how to file
To appeal a Will County assessment, file with the Will County Board of Review online at borcomplaints.willcountysoa.com, by mail or in person; in Illinois the deadline is 30 days after the township assessment list is published (Cook County uses township filing windows). Confirm the exact date on your notice or with the assessor; we add each county's 2027 date here when it is published.
2026 cycle: assessment notices mailed Aug 10, 2026; notice dated and published in local newspapers by township on Aug 12-13, 2026 (publication schedule is posted by the Supervisor of Assessments).
Data as of 20 Oct 2026 · Will County Board of ReviewCheck your own assessment
Free. We compare the value on your notice with recent sales of similar homes nearby and tell you whether an appeal is worth filing. Have your assessment notice and tax bill handy.
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How to file in Will County
- Step 1
File the appeal
Online at borcomplaints.willcountysoa.com with the account number on your notice. State the grounds the county recognises.
- Step 2 · before the hearing
Prepare and submit your evidence
Overvaluation must be shown by a preponderance of the evidence; a uniformity (equity) claim needs clear and convincing evidence. The strongest evidence is a recent arm’s-length purchase of your home, or an appraisal as of January 1. Otherwise use at least three comparable sales, or for equity at least three similar nearby homes with their assessments and property record cards, in a grid. Bring a photo of your home and its property record card.
- Step 3
Meet, then hear
An informal review with Township assessor or Supervisor of Assessments comes first; if you decline the offer, the Will County Board of Review hears the case. Most reductions happen at the first step.
Before you file: how to read your notice · evidence that works · informal vs formal hearing · when not to appeal
Forms
| Form | Number | Use | Format |
|---|---|---|---|
| Residential Complaint Form | — | Board of Review complaint for residential property (2026 version; a new year-stamped form is posted each August) | Fillable PDF |
| Farm Complaint Form | — | Board of Review complaint for farm property (2026 version) | Fillable PDF |
| Commercial Complaint Form | — | Board of Review complaint for commercial property (2026 version) | Fillable PDF |
| Industrial Complaint Form | — | Board of Review complaint for industrial property (2026 version) | Fillable PDF |
| Affidavit of Hearing Waiver | — | Residential or farm owners who want the Board to decide on the written evidence without attending a hearing | |
| Verification of Authority to Represent Owner(s) of Real Property | — | Required when an attorney or law firm files for the owner; must be notarized and signed by an owner of record (rule effective 2026) | |
| Board of Review Complaint Disclosure Form | — | Include with the complaint if the property is held in a real estate trust | |
| Board of Review Complaint Withdrawal Form | — | Withdraw a filed complaint | |
| Residential Appeal (Property Tax Appeal Board) | PTAB-1A | Only after the Board of Review decides: the state appeal, due 30 days after the board’s written notice. Can also be filed online through PTAB eFile. | Fillable PDF |
Appeal levels
| Level | Who hears it | Deadline | Cost |
|---|---|---|---|
| Informal review | Township assessor or Supervisor of Assessments | Before the Board of Review deadline | Free |
| Board of Review | Will County Board of Review | 30 days after the assessment list is published | Free |
| Property Tax Appeal Board | Illinois Property Tax Appeal Board (state) | 30 days after the Board of Review’s written decision | No filing fee |
| Court | Circuit court (administrative review), or a tax objection in Will County circuit court | 35 days after the PTAB decision; tax objections follow the tax-bill penalty date | Court costs |
What evidence the board accepts
Overvaluation must be shown by a preponderance of the evidence; a uniformity (equity) claim needs clear and convincing evidence. The strongest evidence is a recent arm’s-length purchase of your home, or an appraisal as of January 1. Otherwise use at least three comparable sales, or for equity at least three similar nearby homes with their assessments and property record cards, in a grid. Bring a photo of your home and its property record card.
Will County questions
When is the Will County appeal deadline for 2027?
No 2027 date is published yet. The board’s rule: Will County sets one county-wide complaint window per year for all townships (2026: Aug 12 through Sep 14, 2026, which is 30 days after the Aug 12 publication). Complaints must be on the current-year county form with evidence filed at the same time. Mailed complaints count as filed on the USPS postmark date (a complaint with no postmark that arrives after the deadline is not accepted). Faxed or emailed complaint forms are not accepted. Portal submissions are subject to acceptance by the Board; incomplete filings get 10 business days to cure.
How do I appeal my assessment in Will County?
File online at borcomplaints.willcountysoa.com, or file the Residential Complaint Form with the Will County Board of Review, Will County Office Building, ATTN: Supervisor of Assessments Office (Board of Review), 302 N. Chicago Street, Second Floor, Joliet, IL 60432.
Should I talk to the assessor first?
Yes. The township assessor or the Will County Supervisor of Assessments can fix record errors informally. Still file with the Will County Board of Review by the deadline: a board complaint is required before any state appeal.
What evidence works best?
A recent arm’s-length purchase of your home or an appraisal as of January 1. Otherwise, at least three comparable sales, or three similar nearby homes with lower assessments, with property record cards and photos.
How do I contact the Will County Supervisor of Assessments?
Mail: Will County Office Building, ATTN: Supervisor of Assessments Office (Board of Review), 302 N. Chicago Street, Second Floor, Joliet, IL 60432. Phone: (815) 740-4707. Hours and walk-in details: willcountysoa.com.
What if the Board of Review says no?
Appeal to the Illinois Property Tax Appeal Board within 30 days of the board’s written decision. There is no fee, and you can file online through PTAB eFile. A lowered value on an owner-occupied home carries over for the rest of the assessment period.
Check whether yours is over-assessed
Nearby counties
Kankakee County · Grundy County · Kendall County · DuPage County · Cook County · Kane County · LaSalle County
- Will County Supervisor of Assessments homepage
- Will County SOA - Board of Review
- Will County SOA - Assessment Complaint Process
- Will County SOA - Publication Schedule
- Will County Board of Review Complaint Portal
- Complaint Portal - Downloads
- Complaint Portal - FAQ
- 2026 Will County Board of Review Rules and Procedures (PDF)
- 35 ILCS 200/16-55 — Board of Review complaints
- 35 ILCS 200/12-10 — Publication of assessments
- 35 ILCS 200/16-160 — Appeal to the Property Tax Appeal Board
- Illinois DOR — Assessment Appeals
- Property Tax Appeal Board — Filing your appeal
- Property Tax Appeal Board — FAQ
- U.S. Census Bureau, county population estimates (2024) and county gazetteer (2024).