When the Board of Review turns down a Cook County tax appeal, a short clock starts running. The next stop is the Illinois Property Tax Appeal Board, and the PTAB appeal appraisal has to be ready much sooner than most people expect. Here’s how the window works and what PTAB wants to see in the appraisal.
- How the 30-day PTAB deadline is counted in Cook County
- Why the appraisal has to be filed with the petition, not later
- What tax consultants can line up before the clock starts
The 30-Day Clock Has Two Possible Start Dates
Illinois law sets the deadline in 35 ILCS 200/16-160. In most counties, you get 30 days after the written notice of the Board of Review decision. Cook County works a little differently.
In Cook, the appeal is due within 30 days of the Board’s notice or 30 days after the Board sends its final action on the township to the Assessor, whichever is later. So two parcels decided the same week can have different deadlines. PTAB also asks Cook County filers to include the Board’s final decision. If you file after the township is certified, it wants the township close date too, according to its practice and procedures page.
Timing is live right now. The Cook County Board of Review’s third group of 2026 townships, which includes Lyons, Northfield, Stickney, and West Chicago, closes for filing on November 6. Decisions for earlier groups will keep arriving through the season, and each one starts its own count. With the south suburbs reassessed this year, as we covered in our piece on the 2026 south suburbs reassessment, plenty of owners will be looking at that next step.
Two other points in the same statute are worth a quick look. Missing a Board of Review hearing you were properly notified of can cost you PTAB jurisdiction. And a taxpayer who files at PTAB gives up certain valuation objections in court. Which route fits a given case is counsel’s call, not the appraiser’s.
PTAB Starts Fresh, but Its Record Closes Early
PTAB hears appeals de novo, as if the Board of Review never decided the case. The Cook County Board of Review’s own PTAB page notes that PTAB isn’t limited to the evidence the Board saw. So a thin Board of Review file can still become a strong PTAB case.
The catch is timing. Under PTAB Rule 1910.30, your evidence goes in with the petition. If the appraisal isn’t done, you need to ask for an extension in writing at the same time you file. PTAB then grants 30 days. Without that request, no evidence is accepted after the petition is filed.
Rebuttal won’t rescue a late appraisal either. Rule 1910.66 says rebuttal can’t be new evidence such as an appraisal. It can, however, include a review appraisal or a written critique of the other side’s appraisal by a real estate appraisal expert. Generally, the hearing itself won’t take new documents either. That’s why the record matters so much on day one.
What a PTAB Appeal Appraisal Needs to Include
PTAB calls an appraisal generally the best evidence of market value, but it is specific about what counts. A letter of opinion isn’t enough, because the Board can’t check the data behind it. A full appraisal should examine the cost, income, and sales comparison approaches where possible, and show the data it relied on.
The value also has to land on the right date. PTAB weighs market value as of the January 1 assessment date, so a report built for a loan or a sale may not line up. Our article on what a tax appeal appraisal must contain walks through those basics. Our explainer on mass appraisal versus a single-property appraisal shows why the Assessor’s number and market value can drift apart.
Adjustments matter too. In one Cook County decision, Docket 20-32775, PTAB favored an appraisal with detailed adjustments to four sales over the Board of Review’s raw, unadjusted sales data. Comparable sales still need a reason behind every adjustment.
Commercial appeals carry an extra warning. PTAB says vacancy alone isn’t enough. Neither is an income statement prepared by an attorney, unless market data supports it. So the rent, vacancy, and expense figures should tie back to the market, the way our guide to the income approach for commercial property lays out.
Plan for the Appraiser to Testify
PTAB doesn’t require the appraiser to testify. Still, it calls testimony a best practice and recommends it. When the appraiser doesn’t appear, the appraisal may carry less weight. Also, an appraiser can testify to value only if a signed appraisal was submitted on time.
Some practical details come with a hearing. When $100,000 or more of assessed value is at issue, the appellant has to provide a court reporter. So it helps to confirm the appraiser’s availability before the hearing date is set, not after.
Be Honest About How Long PTAB Takes
PTAB is not quick. After filing, the Board of Review has 90 days to respond, and extensions are possible. Then each side gets 30 days for rebuttal before a hearing or a decision on the record. In Docket 20-32775, a 2020 tax year appeal, the final decision was issued in August 2024.
That wait has a few upsides and a few traps. If PTAB lowers an assessment, the county treasurer refunds the excess with interest. But for commercial and industrial property, the Property Tax Code doesn’t require a PTAB reduction to carry into later years. Owners appeal each year on its own, though PTAB lets them file the same evidence if it reflects value for that year. Plan the appraisal budget with that in mind.
For Tax Consultants, Line Up the File Before Day One
Tax consultants often see the Board of Review decision first, so they set the pace. PTAB’s rules draw a clear line here. An LLC, corporation, or partnership must be represented by an Illinois-licensed attorney. Tax representatives and appraisers may testify and assist counsel, but they can’t question witnesses.
That leaves real work you can own. First, log the notice date and the township close date the day the decision arrives. Second, pull the Board’s final decision and send it to the attorney with your deadline math. Third, get the appraiser the rent roll, recent operating statements, and any lease changes right away. If the appraisal can’t finish in time, tell counsel early, so the extension request goes in with the petition.
Board of Review Decision Just Arrived?
PahRoo prepares tax appeal appraisals valued as of January 1, with the data PTAB expects to see and an appraiser ready to testify. Send us the decision date and the property, and we’ll work to your filing window.
Frequently Asked Questions
How long do I have to appeal a Board of Review decision to PTAB?
In Cook County, 30 days after the Board of Review’s written notice or 30 days after the Board sends its final action on the township to the Assessor, whichever is later. In other Illinois counties, it’s 30 days after the written notice.
Can I give PTAB evidence the Board of Review never saw?
Yes. PTAB hears appeals de novo and isn’t limited to the Board of Review’s evidence. But the evidence has to be filed with the petition, or within an extension you request when you file.
Can I add an appraisal later as rebuttal?
No. PTAB’s rules bar new evidence such as an appraisal in rebuttal. Rebuttal can include a review appraisal or a written critique of the other side’s appraisal.
Does the appraiser have to testify at PTAB?
It isn’t required, but PTAB recommends it as a best practice. If the appraiser doesn’t appear, the appraisal may be given less weight.
How long does a PTAB appeal take?
It varies, and it can take years. In one Cook County case, a 2020 tax year appeal was decided in August 2024. If the assessment is lowered, the county treasurer refunds the excess with interest.
Cook County Appraisals From Board of Review to PTAB
PahRoo Appraisal & Consultancy works with property tax attorneys and tax consultants from our Lincolnwood office, and we also appraise in Dallas, Philadelphia, Phoenix, and Naples. Michael Hobbs, MAI, SRA, signs our Illinois reports and is available to testify. Learn more about our Chicago and Cook County appraisal team.