What percentage of property tax appeals actually win a reduction?

It depends entirely on the jurisdiction and how its board processes appeals, and most large jurisdictions don't publish this number at all. Where official records do exist: Florida statewide petitions that reached a hearing won 44.1% of the time in 2023 (all property types); Cook County, IL residential appellants won 51.4% of the time in Tax Year 2023; New York City Tax Class 1 (1-3 family home) applications won 2.9% of the time in 2024, because NYC's Tax Commission works through a backlog rather than deciding nearly every filed case that year.

Is the "40-60% national appeal success rate" figure real?

No verifiable primary source publishes a national appeal success rate. The "40-60%, per IAAO and Lincoln Institute of Land Policy" figure circulating on several property-tax websites does not trace to any page on iaao.org or lincolninst.edu that could be found and opened directly — it appears only on a small cluster of property-tax consulting firm sites that repeat it from each other. The National Taxpayers Union Foundation publishes a real, related but different claim: that most people who do appeal win at least a partial reduction, without giving a specific percentage.

Sourced Data

Property tax appeal success rates, from the source

"40-60% of appeals succeed" shows up everywhere in property-tax content, with no citation that survives an open link. We checked twelve of the largest U.S. jurisdictions directly against their own published records instead. Three publish a usable number. Here they are, with the source open next to each one.

Jurisdiction	Year	Appeals	Won a reduction	Source
Florida (statewide) All property types — Value Adjustment Board petitions, all 67 counties combined	2023	72,189 heard of 135,517 petitions filed	44.1%	Florida Dept. of Revenue — 2024 County Profiles, "2023 Value Adjustment Board Results and Comparison," statewide overview page
Cook County, IL Residential appellants (excludes condos)	Tax Year 2023	216,125 residential parcels appealed	51.4%	Cook County Board of Review — Tax Year 2023-Fiscal Year 2024 Annual Report, p.8-9, "Appeals Resulting in a Reduction"
New York City Tax Class 1 — one-to-three family homes, the closest NYC category to a homeowner	2024	1,509 applications filed	2.9%	New York City Tax Commission — 2024 Statistical Profile, Table A1 / A4

Why the three numbers are so different

Florida (statewide) (44.1%). Every VAB petition that reaches a hearing gets an up-or-down decision that tax year — closest of the three to a straight win rate, but Florida does not break this out by property type, so it is not residential-only.

Cook County, IL (51.4%). The Board of Review decides essentially every filed appeal that tax year — no backlog carried forward, no settlement-offer step. That's why its rate reads close to Florida's, structurally.

New York City (2.9%). NYC's Tax Commission works through a backlog and negotiates settlement offers rather than deciding nearly every filed case in the same cycle — only 58 of 1,509 Class 1 applications even received an offer this year, and 43 were accepted. A real, official number; a structurally different process from the other two.

None of these numbers is more "correct" than another — they measure genuinely different processes. What they share is that each is a real figure from the jurisdiction's own published records, not a number repeated from another website.

What most large jurisdictions actually publish: nothing

We checked twelve of the largest U.S. jurisdictions by population for a published reduction rate. Nine did not have one we could verify. Five of those are worth naming, because their own third-party "success rate" numbers circulate widely online without ever tracing back to something official:

Philadelphia, PA (Board of Revision of Taxes)
City budget testimony reports what share of the appeal backlog gets a hearing each year — not what share of hearings win.
Los Angeles County, CA (Assessment Appeals Board)
No statistics report found on the Board’s own site or the Board of Supervisors’ assessment-appeals pages.
Maricopa County, AZ (Assessor)
Publishes the number of appeals received each year, on the record, that it does not publish a reduction rate alongside them.
Harris, Dallas and Travis Counties, TX (appraisal review boards)
Each county’s own annual report (checked directly) publishes protest volume and the average size of a reduction, not the share of protests that won one.
King County, WA (Board of Appeals and Equalization)
The only official figure found is an 8-year-old County Auditor audit covering 2012-2017, combining residential and commercial — too old and too broad to stand next to 2023-2024 numbers.

The higher figures that show up for these counties online — 66-89% ranges, and the widely repeated "40-60% national rate, per IAAO and Lincoln Institute of Land Policy" — all trace back to the same small cluster of property-tax consulting firm websites, never to a page on the county's, state's, IAAO's or Lincoln Institute's own site that we could open and confirm. We checked. That is not a citation; it is a number reprinted enough times to look like one.

Where your county lands

National and even state-level numbers describe the market, not your house. Run the free analysis on your own address to see whether your specific assessment is out of line with comparable sales — a real, checkable answer, not a percentage borrowed from somewhere else.

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See also our methodology for how each report's own success estimate is produced.