Rob Hartley
Founder, AppealDesk · February 13, 2026
Property Tax Appeal Statistics: Win Rates, Savings & Data (2026)
Updated February 2026 · 10 min read
Between 30-60% of U.S. properties are overassessed, but fewer than 5% of homeowners ever file an appeal. The national average success rate for appeals is 40-60%, with average savings of $1,000-3,000 per year. These numbers mean most homeowners are leaving money on the table — often thousands of dollars per year, compounding over the life of their ownership.
Overassessed
30-60%
of U.S. properties
Appeal Success
40-60%
national average
Who Appeals
<5%
of homeowners
Avg Savings
$1-3K
per year
National Overassessment & Appeal Statistics
According to the National Taxpayers Union Foundation, 30-60% of taxable property in the United States is overassessed. Sanguine Strategic Advisors found that successful appeals yield an average 10-15% reduction in assessed value. Despite these numbers, the overwhelming majority of homeowners never challenge their assessment.
The gap between overassessment rates (30-60%) and appeal rates (<5%) represents a massive transfer of wealth from homeowners to local governments. Data from the U.S. Census Bureau’s American Community Survey shows that U.S. homeowners pay over $600 billion annually in property taxes — making even small overassessment percentages worth billions nationwide. For context: if even 20% of overassessed homeowners filed appeals and achieved average savings of $1,500/year, the total annual savings would be in the tens of billions of dollars nationally.
Estimated Annual Overpayment by State
The table below shows estimated annual overpayment for homeowners in the 15 highest property tax states, assuming a 10-20% overassessment on a typical home (based on Zillow Home Value Index adjusted for AppealDesk’s customer profile).
| State | Typical Home Value | Eff. Tax Rate | Est. Annual Overpayment | 10-Year Cost |
|---|---|---|---|---|
| New Jersey | $755,450 | 2.23% | $1,685–$3,369 | $16,850–$33,690 |
| Illinois | $414,700 | 2.07% | $858–$1,717 | $8,580–$17,170 |
| Connecticut | $601,750 | 1.92% | $1,155–$2,311 | $11,550–$23,110 |
| New Hampshire | $700,350 | 1.89% | $1,324–$2,647 | $13,240–$26,470 |
| New York | $835,200 | 1.64% | $1,370–$2,739 | $13,700–$27,390 |
| Texas | $490,100 | 1.63% | $799–$1,598 | $7,990–$15,980 |
| Wisconsin | $450,950 | 1.59% | $717–$1,434 | $7,170–$14,340 |
| Nebraska | $419,050 | 1.54% | $645–$1,291 | $6,450–$12,910 |
| Pennsylvania | $410,350 | 1.41% | $579–$1,157 | $5,790–$11,570 |
| Iowa | $330,600 | 1.49% | $493–$985 | $4,930–$9,850 |
| Ohio | $349,450 | 1.43% | $500–$999 | $5,000–$9,990 |
| Michigan | $361,050 | 1.35% | $487–$975 | $4,870–$9,750 |
| Kansas | $404,550 | 1.34% | $542–$1,084 | $5,420–$10,840 |
| Maine | $552,450 | 1.17% | $646–$1,293 | $6,460–$12,930 |
| Minnesota | $513,300 | 1.05% | $539–$1,078 | $5,390–$10,780 |
Sources: Zillow ZHVI Q1 2025 × 1.45 ICP multiplier, U.S. Census Bureau ACS effective property tax rates 2024, 10-20% overassessment range per NTU Foundation / Sanguine Strategic Advisors.
Appeal Success Rates Vary Dramatically by County
National averages obscure enormous county-level variation. Some examples:
Hays County, TX
98.68%
protests result in reduction
Cook County, IL
62%
of appeals succeed
National Average
40-60%
of appeals succeed
Why the variation? Counties with less accurate mass appraisal models produce more overassessments — and more successful appeals. Texas has consistently high success rates because its protest system is designed to be homeowner-friendly, and property values in fast-growing metros like Harris County fluctuate faster than the appraisal district can model.
Cook County, IL has a notoriously complex assessment system with a triennial reassessment cycle and classification-based ratios. Even at 62%, appeals succeed more often than not — a strong argument for filing regardless of your county.
How Evidence Type Affects Win Rates
Not all appeal evidence is created equal. The strongest cases combine multiple evidence types:
Comparable sales (strongest)
Recent sales of similar homes near yours that sold for less than your assessed value. This is what hearing boards weigh most heavily.
Assessment ratio analysis
Demonstrating that your assessed-to-market-value ratio exceeds the county median. The IAAO (International Association of Assessing Officers) publishes standards on ratio studies that define acceptable uniformity. This “unequal appraisal” argument is powerful in states that require assessment uniformity.
Property condition evidence
Photos and documentation of condition issues (deferred maintenance, foundation problems, environmental factors) that the assessor’s model didn’t capture.
Data errors
Incorrect square footage, bedroom/bathroom count, lot size, or year built on your property record card. Factual errors are the easiest appeals to win.
The Compound Cost of Not Appealing
Property tax overassessment isn’t a one-time cost — it compounds. A $2,000/year overassessment costs $20,000 over 10 years. In New Jersey, where the effective tax rate is 2.23%, a 15% overassessment on a typical home costs roughly $2,530 per year — $25,300 over a decade. In Illinois (2.07% rate), the 10-year cost is similar.
A successful appeal typically results in a 10-15% reduction in assessed value. That reduction stays in effect until the next reassessment — which may be 1-3 years away depending on your state. In states with triennial or longer reassessment cycles (Illinois, Maryland, some New York jurisdictions), a single successful appeal can save you thousands over the full cycle.
Why So Few Homeowners Appeal
If 30-60% of properties are overassessed and 40-60% of appeals succeed, why do fewer than 5% of homeowners file? Research and surveys point to several reasons:
- They don’t know they can. Many homeowners assume their assessment is final and don’t realize they have the legal right to challenge it.
- The process seems complicated. Finding comparable sales, understanding assessment ratios, and navigating county filing procedures discourages many homeowners from starting.
- They think it won’t work. Without data on success rates, homeowners assume the system favors the assessor. In reality, well-prepared cases succeed more often than not.
- They don’t think the savings justify the effort. But even a $500/year reduction compounds to $5,000 over 10 years — for what is often less than an hour of effort with the right tools.
Services like AppealDesk and others have lowered the barriers significantly. AppealDesk’s $49 flat-fee property tax appeal evidence packets eliminate the research burden, and county-specific filing guides eliminate the process confusion. The $49 investment (or free DIY) against potential thousands in annual savings makes the math overwhelmingly favorable. See our complete guide to property tax appeals for step-by-step instructions.
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Frequently Asked Questions
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Data sources: National Taxpayers Union Foundation (overassessment estimates), Sanguine Strategic Advisors (appeal outcomes), Zillow ZHVI Q1 2025, U.S. Census Bureau ACS (effective tax rates), county appraisal district records (county-specific success rates).