Jefferson County property tax appeal 2027: deadline, forms and how to file
To appeal a Jefferson County assessment, file with the Jefferson County Board of Review by mail, by email 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.
County BOR page states 'Appeal deadline for 2025 assessments is April 6, 2026', so Jefferson's assessment publication/appeal window can fall in late winter/spring rather than summer. The 2026 publication date had not been posted as of 2026-10-20.
Data as of 20 Oct 2026 · Jefferson 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 Jefferson County
- Step 1
File the appeal
Use the method your notice lists, by the deadline on the notice.
- 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 Jefferson 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 |
|---|---|---|---|
| Assessment Complaint (Board of Review) | — | Assessment complaint filed with the Jefferson County Board of Review | |
| 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 | Jefferson 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 Jefferson 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.
Jefferson County questions
When is the Jefferson County appeal deadline for 2027?
No 2027 date is published yet. The board’s rule: Forms and evidence must be returned within 30 days of the newspaper publication date, Mon-Fri 8:00-4:00, to Board of Review, 100 S 10th St., Room 2, Mount Vernon, or by email to the clerk (lacrunk@jeffersoncounty.illinois.gov); USPS mail counts as filed on the postmark date. Evidence may follow no more than 14 calendar days after the filing deadline (2025 rules).
How do I appeal my assessment in Jefferson County?
File the Assessment Complaint (Board of Review) with the Jefferson County Board of Review, Board of Review, 100 S 10th St., Room 2, Mount Vernon, IL 62864. Mailed complaints count as filed on the postmark date.
Should I talk to the assessor first?
Yes. The township assessor or the Jefferson County Supervisor of Assessments can fix record errors informally. Still file with the Jefferson 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 Jefferson County Assessor (Supervisor of Assessments)?
Mail: Board of Review, 100 S 10th St., Room 2, Mount Vernon, IL 62864. Phone: 618-244-8016 ext. 7. Hours and walk-in details: jeffersoncounty.illinois.gov.
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
Franklin County · Marion County · Hamilton County · Washington County · Wayne County · Perry County · Clinton County
- Jefferson County Board of Review
- Jefferson County Assessor
- Jefferson County Applications & Forms
- Jefferson County Board of Review Rules & Procedures 2025 (docx)
- Jefferson County Assessment Complaint form (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).