PTAB: what happens after the Board of Review says no
A state-level appeal, free to file, slow, and it hears the case fresh.
If your county Board of Review denies you, the Illinois Property Tax Appeal Board is the next step.
What it is
A state body that hears assessment appeals independently of the county. It considers the case fresh — it is not reviewing the board for error, it is deciding value again.
Deadline
Generally 30 days from the Board of Review's written decision. Same discipline as before: the clock starts on the decision, not on your reading of it.
Cost
Filing is free for residential appeals. The real cost is time.
Time
Slow. Cases can take a year or more, and sometimes several. You pay your bill in the meantime; if you win, the correction comes later as a refund.
Evidence
The standard is higher than at the board. Comparable sales and assessments must be properly documented, and for anything other than a straightforward residential case an appraisal is close to expected.
Representation
Individuals may self-represent. Corporations, LLCs and trusts generally need an attorney.
Is it worth it
If the annual saving is meaningful and persists — and assessments tend to persist — a multi-year wait can still be worth it. If it is a hundred dollars a year, it is probably not.