The success rate on an appeal company's website is almost never a government figure. When you go looking for what official assessment boards actually publish, two things stand out. First, most places — including Texas, the largest protest market in the country — don't publish a real win rate at all. Second, the one big jurisdiction that rigorously audits both of its appeal stages, New York City, found that homeowners who stopped at the city's administrative board won a reduction about 10% of the time, while those who pushed on to the state's small-claims judicial review won 93% of the time. That gap is not proof that a courtroom is magic — the people who escalate are a self-selected, better-prepared group — but it is a loud reminder that a first “no” is often not the end of the road.
Type “property tax appeal success rate” into a search engine and you'll get a wall of confident numbers: 70% of appeals succeed, 60%, four out of five. Nearly every one of those figures is published by a company that will file your appeal for a cut of the savings. That doesn't make the numbers dishonest — but it does mean they are marketing, computed by the seller, describing the seller's own hand-picked clients. They are not a neutral answer to the question you're actually asking: if I appeal, will it work?
So we went looking for the version of that number that comes from the government — the assessment boards, appeal boards, and comptrollers who actually decide these cases. Here is what they publish, what they don't, and how to read your own odds honestly.
Property tax appeals are decided by public bodies: a county board of review, a state appeal board, a value adjustment board, an appraisal review board. In principle, every one of them sits on the raw data — how many appeals were filed, how many got a reduction, how big the reductions were. In practice, very few package that into a clean, published “win rate.”
That vacuum is where the marketing numbers come from. When a service advertises a “65% success rate” in a county whose board publishes no such figure, the number is almost always the firm's own calculation — sometimes built on the government's public case data, sometimes on its own book of business, and almost always with a methodology it doesn't disclose. Two things get quietly baked in:
None of this means appeal companies are lying, and for homeowners who won't file on their own a good one can absolutely be worth it. It just means the advertised percentage isn't your personal probability of success. For a closer look at how these firms present themselves, see our comparison of property tax appeal services.
Here is the government-sourced picture, jurisdiction by jurisdiction. Note how uneven it is — and how the cleanest numbers come from the places that treat appeal data as a public accountability matter, not a marketing asset.
| Jurisdiction | What the government publishes | Stage | Source |
|---|---|---|---|
| New York City | ~10.3% of Class 1 (1–3 family) owners who completed administrative review got a reduction offer; 93.4% of the 768 owners who filed small-claims judicial review got a reduction | Both admin & judicial | NYC Comptroller audit, Dec 2025 |
| Iowa | ~35% of appeals to the state board received a modified (lower) assessment via settlement or order, 2019–2023 | State appeal board | Iowa Property Assessment Appeal Board |
| New Jersey | 15,717 appeals filed in 2025, with roughly $2.06B in assessed-value reductions granted by county boards (a valuation cut, not a dollar-for-dollar tax refund) | County tax boards | NJ Division of Taxation, 2025 summary |
| California (LA County) | Publishes counts of appeals filed and resolved per county (LA County handled well over 30,000 board cases on the 2023 roll), but not a pre-computed win rate | County appeals boards | CA Board of Equalization, “Table L” |
| Cook County, IL | Posts every appeal decision as raw open data, but publishes no official win-rate statistic — the “39%” and “60–70%” figures in circulation are outside calculations, not the board's own | Board of Review | Cook County Open Data portal |
| Texas | No official statewide protest win rate. The Comptroller studies appraisal accuracy, not appeal outcomes — so every “Texas success rate” you see is a commercial estimate | Appraisal Review Boards | Texas Comptroller (does not publish) |
The honest takeaway from this table is not a tidy national average — it's that no such average exists in any verifiable form. Where governments do publish, a rough pattern shows up: with real evidence behind them, something like a third to two-thirds of appeals earn some reduction. But the size of that reduction, and whether it's worth your afternoon, varies enormously.
One jurisdiction did something the others don't: it measured what happens at each stage of the process. In December 2025, the New York City Comptroller audited how the city handles residential assessment appeals and reported two numbers side by side. Among Class 1 homeowners who completed the city's administrative review, about 10.3% received a reduction offer. Among those who instead pursued a Small Claims Assessment Review (SCAR) — a low-cost judicial path in state court — 93.4% got a reduction.
It is tempting to read that as “skip the board, go to court, win nine times as often.” Don't. The gap is real, but it is heavily shaped by who ends up in each pool:
What the number does tell you, cleanly, is this: an administrative denial is frequently overturnable. A striking share of the people who refused to treat the first “no” as final went on to win. And in New York, the escalation path is unusually accessible — SCAR is designed for homeowners to use themselves, with a nominal filing fee and no lawyer required. That is not true everywhere: in many states the next step after the local board is a formal tax court or state board with real procedural demands. Before you assume you're out of options, find out what your second stage looks like — our guide to what to do after a property tax appeal is denied walks through it.
Because a clean national success rate doesn't exist, the useful question isn't “what's the average?” It's “what actually decides my case?” Three factors do most of the work:
You can often get closer to a real answer than any marketing page. Try, in order:
If your jurisdiction publishes nothing — as many don't — treat that as its own signal: any confident percentage you're being shown for that place is an estimate, and you should ask who made it and how.
Plenty of homeowners look at all this and decide they'd rather pay someone. That can be a perfectly sound choice — the point of this site is that you should make it with clear eyes, not marketing math. Two honest reminders. First, a firm's advertised win rate reflects the cases it chose to take, so it overstates the odds for a marginal property it might have declined. Second, the economics matter as much as the odds: on a contingency fee you keep only part of any reduction, and the math changes with the size of your likely win. We lay out both sides in our DIY-versus-hire decision matrix and the underlying contingency-fee savings math.
Whichever way you go, the core finding holds: the most important number in a property tax appeal isn't the success rate on anyone's homepage. It's whether the evidence in your file actually shows your home is over-assessed — and whether you're willing to use every stage of review your jurisdiction gives you.
A note on our numbers. Every figure above traces to a government source — a comptroller's audit, a state appeal board, a tax department summary, or a county open-data portal. Where a widely-circulated statistic turned out to be a commercial calculation rather than an official publication, we've said so rather than repeat it as fact. Appeal outcomes and the reports behind them change; confirm your own jurisdiction's current figures before relying on them.
There is no reliable national figure, because most jurisdictions don't publish one. Among the governments that do, roughly a third to two-thirds of appeals earn some reduction when they're backed by real evidence — but “some reduction” can mean anything from a token trim to a meaningful cut. Any single confident percentage you see is almost always a commercial estimate for a specific market, not an official rate.
Two reasons. They screen out cases they expect to lose, so the pool they report on is pre-selected to win; and they define “success” as any reduction, including small ones. The result is a number that's true about their book of business but overstates the odds for an average homeowner — especially one with a borderline case.
Usually not. Most states offer at least one more level of review — a state appeal board, a small-claims assessment review, or a tax court. New York City's own audit found that homeowners who escalated to judicial review won reductions far more often than the administrative-only pool. Check what your jurisdiction's next stage is and what it requires before you give up.
It can, especially if you'd otherwise not file at all or wouldn't assemble strong evidence. But a firm's headline win rate isn't your odds — it reflects the cases it agreed to take. The thing that most reliably moves any appeal, whether you file it or a service does, is the quality of the comparable-sales evidence behind it.