What is the deadline to appeal my property assessment in Illinois?
What is the deadline to appeal my property assessment in Illinois?
Illinois has no single statewide appeal date — your deadline is roughly 30 days after your township's assessment notice or roll publication, so you must look up your specific township's open and close dates rather than rely on a fixed calendar date.
Illinois does not use one statewide property-tax appeal deadline. Instead, the window is tied to your township and runs about 30 days from the relevant trigger date. Missing it usually forfeits the appeal for that year (outside the narrow Certificate-of-Error path).
In Cook County. Appeal windows open township by township. The Assessor advises taxpayers "typically have 30 days to file an appeal after receiving your reassessment notice. The last date to file an appeal for that year is printed on your notice." After the Assessor's window closes, the separate Board of Review opens its own township windows. Find your township's exact open and close dates on the Assessment & Appeal Calendar and the Board of Review deadlines.
Outside Cook County. In collar and downstate counties, the deadline is generally 30 days after the township assessment roll is published in the local newspaper — not 30 days from when you receive mail. For example, DuPage County's window "ends thirty days after the publication of the township assessment roll." Confirm with your county supervisor of assessments / Board of Review.
Escalation deadline. Whichever county you are in, once the Board of Review issues its written decision you have 30 days to appeal to the state Property Tax Appeal Board under 35 ILCS 200/16-160, or to choose the pay-under-protest court route.
How to pin down your date: 1. Find your Property Index Number (PIN) and township on the Assessor's site. 2. Look up that township's current window on the official calendar. 3. Calendar the close date and file several days early. 4. After any decision, note the 30-day clock for the next stage.
Because the date moves with your township and the roll-publication or notice date, the single most important step is to look up your own township rather than assume a fixed deadline.