Illinois · property tax · 2027
Illinois property tax appeal deadline 2027.
There is no single statewide date. You file with the county board of review within 30 calendar days after the assessment list is published for your township.
Statute-based estimate
This page is arithmetic and a plain-English reading of the statute. It is not legal, tax or financial advice. Your county board of review publishes the date that actually applies to you.
Find your complaint deadline
The Illinois rule
Section 16-55(d) of the Property Tax Code (35 ILCS 200/16-55) says a complaint to affect the assessment for the current year must be filed on or before 30 calendar days after the date of publication of the assessment list under section 12-10. Because each county publishes township by township, the calendar date differs across Illinois. The Illinois Department of Revenue tells owners to file a written complaint on Form PTAX-230 with the county board of review.
What the calculator does
Enter the publication date from your county and it adds 30 calendar days. The statute does not say what happens when day 30 falls on a weekend, and this page does not guess: if your date lands on a weekend, file on the Friday before.
Worked example
If your township list is published on July 15, 2027, the thirtieth calendar day after is August 14, 2027, a Saturday. File by Friday, August 13.
How filing is counted
Under 16-55(d-5), a complaint sent by U.S. mail is treated as filed on its postmark date, and one sent by another delivery service is treated as filed on the date shown on the shipper's tracking label. Electronic filing counts as filed on the date received only if the board of review's rules allow it.
Evidence checklist (from the Department of Revenue)
- The property record card and a photograph of your property.
- Record cards and photographs of similar properties in your neighborhood.
- A copy of the real estate transfer declaration, deed or purchase contract.
- An appraisal of the property.
- A list of recent comparable sales, with photographs, record cards and sale prices.
After the board of review
If you disagree with the board's decision you can appeal in writing to the Property Tax Appeal Board or file a tax objection complaint in circuit court. You must pay your taxes while the appeal is pending. Appealing to the board of review first is a prerequisite to either step.
Limits of this page
- Farm land and buildings use Form PTAX-227, not PTAX-230.
- Your county board of review, not this page, publishes the date your list was published.
- This page does not predict when your list will be published.
Frequently asked questions
What is the Illinois property tax appeal deadline?
A complaint must be filed with the county board of review on or before 30 calendar days after the assessment list is published for your township (35 ILCS 200/16-55(d)). The calendar date varies by township.
Where do I file an Illinois assessment complaint?
With your county board of review, in writing, on Form PTAX-230 for non-farm property.
Is a mailed Illinois complaint filed on the postmark date?
Yes. Under 16-55(d-5), mail sent through the U.S. Postal Service is treated as filed on its postmark date.
What if I miss the board of review deadline?
The statute sets the deadline for the current-year assessment. Check with your county board of review about late options; this page does not cover them.
Sources
Read November 2, 2026. Figures and rules on this page come from these pages and no others; what each one could not confirm is stated above.