Assessment appeal savings

If you appeal your property tax assessment successfully, how much would you actually save? This calculator shows annual and long-term savings at any reduction percentage.

Model your appeal savings

Your current annual property tax bill
Typical successful appeals: 5–15%
Typical 2–4% per year
Many firms take 30–50% of first-year savings. Leave 0 if DIY.
Year 1 net savings
$0
5-year: $0 · 10-year: $0 · New annual tax: $0

A property tax appeal — a "protest," "valuation challenge," or "grievance" depending on the state — argues that your county's assessed value of your home is too high, backed by comparable sales, condition issues, or property record errors. If it succeeds, every future tax bill tied to that valuation drops until the next full reassessment cycle. Reported residential appeal success rates vary widely by jurisdiction and assessment cycle — county- and state-level reports typically show some-reduction rates in the 30–60% range, with successful reductions clustering around 5–15% of assessed value (the International Association of Assessing Officers catalogs the methodology, and the Texas Comptroller's ARB report is the most-cited annual hearing-volume publication).

Enter your current annual tax, the reduction you expect to achieve, an annual growth rate, and any service fee to model year-1 net savings plus 5- and 10-year cumulative totals. The explainer below covers the three filing paths (DIY, contingency service, attorney), the evidence that actually moves assessors, deadline calendars for the biggest states, and the common mistakes that sink otherwise winnable appeals.

How an appeal works

A property tax appeal — also called a tax assessment protest or valuation challenge — argues that your county's assessed value of your home is too high. The argument is made to a local board (assessor, appraisal review board, board of review, board of equalization — names vary), backed by evidence: recent comparable sales, condition issues, errors in the property record card. If you win, your assessed value drops, and so does every future tax bill tied to that valuation until the next full reassessment cycle.

The ROI is dramatic because the savings compound over time. A one-time appeal effort reduces your bill for every year until the next reassessment — often 1–5 years depending on your jurisdiction's cycle. Even a modest 8% reduction can save $4,000–$7,000 over a decade. The effort is usually 5–15 hours of focused work.

Three paths to file

  • DIY appeal: Free. You pull comps from the county records and Zillow, fill out the protest form, attend the hearing. By far the most common path for residential properties under ~$1M.
  • Contingency-fee service (Ownwell, ProtestYourAppraisal, Hometown Property Tax): They take 30–50% of first-year savings, zero if they don't win. Lower effort, lower upside, but you keep all savings from year 2 onward.
  • Property tax attorney: Flat or hourly fee. Used mainly for commercial properties or high-value residential homes where the savings justify the cost and the legal complexity (multi-parcel, special-use designation, equity arguments) is high.

Typical success rates

Outcome rates vary widely by county, year, and whether the appeal goes to informal review or a formal hearing — there's no single national success-rate figure. As a rough benchmark from county-published reports:

  • Residential appeals that result in some reduction commonly fall in the 30–60% range
  • Successful reductions typically cluster around 5–15% of assessed value
  • Texas and Florida have high appeal volume and well-documented hearing processes (Texas Comptroller ARB report)
  • Hearing-based appeals tend to do better than informal review when the evidence is strong and well-organized

What evidence works

  • Recent comparable sales — homes within ½ mile, similar size and age, sold in the last 6–12 months for less per square foot than your assessment implies
  • Property condition issues — outdated kitchen/bath, deferred maintenance, structural defects, settling, dated systems, photos and contractor estimates
  • Property record card errors — incorrect square footage, bedroom/bath count, lot size, construction year, condition rating
  • Equity argument — comparable neighboring homes assessed lower than yours (works best in TX, available in some other states)
  • Recent appraisal — if you refinanced, an independent appraisal showing a value below the county's number is strong evidence

Deadlines and timing

Deadlines vary, almost always tied to the assessment notice. Typical windows:

  • Texas: May 15 or 30 days from notice, whichever is later
  • Florida: 25 days from TRIM notice (typically September)
  • California: July 2 – November 30 for regular roll appeals
  • Illinois (Cook County): 30 days per township during the open assessment season
  • New York: Grievance Day (usually 4th Tuesday in May for most municipalities)

Miss the window and you generally wait a year. A few states allow late filings only with cause (e.g., you didn't receive the notice). Calendar the deadline as soon as your annual notice arrives.

Worked examples

Example 1 — DIY win in Texas. Annual tax $9,200, successfully reduced by 12%, no fee, 3% expected growth:

  • Year 1 net savings: $1,104
  • 5-year cumulative: ~$5,864
  • 10-year cumulative: ~$12,650

Example 2 — Contingency-fee service. Same homeowner uses a 40%-of-year-1 contingency firm:

  • Year 1 gross savings: $1,104
  • Year 1 fee: $441 (40%)
  • Year 1 net: $662
  • Years 2–10 still yield full savings to the homeowner
  • 10-year cumulative net: ~$12,200

Example 3 — Modest reduction, big lifetime impact. Annual tax $14,500 (NJ high-tax town), 6% reduction achieved, 2.5% growth:

  • Year 1 savings: $870
  • 5-year cumulative: ~$4,600
  • 10-year cumulative: ~$9,800

Even a "small" reduction is enormously valuable in a high-tax jurisdiction because the absolute dollars compound through reassessment cycles.

Common mistakes

  • Arguing market value, not assessed value. Many homeowners walk into a hearing saying "my home isn't worth that much." The board doesn't care — they care about the assessed value, the assessment ratio, and how it compares to recent sales. Argue in their framework.
  • Bringing the wrong comps. Comps must be similar: size (within 20% sqft), age (within 10 years), neighborhood, condition. Different style, different lot, or different school district = not a comp. Use 3–5 strong comps, not 12 weak ones.
  • Skipping the informal review. Most counties offer an informal pre-hearing review with the assessor. Win there and you don't need a hearing. Almost always faster and friendlier than the full appeal process.
  • Forgetting the property record card. Pull it. Verify every line. Wrong sqft, wrong bedrooms, missed depreciation — clerical errors are the easiest wins and often don't even require a full appeal.
  • Missing the deadline. The single most common appeal mistake. Calendar it the day your assessment notice arrives.
  • Showing up unprepared. A hearing isn't a chat — it's a documented, evidentiary proceeding with a board that hears dozens of cases a day. Print your evidence. Have a one-paragraph opening. Walk them through your number and why.

Frequently asked questions

How much does it cost to file an appeal?

DIY: $0 to file. Contingency services: 30–50% of year-1 savings if they win, $0 if they don't. Attorneys: usually $500–$3,000 flat or $200–$500/hour for residential cases.

Will the assessor raise my value to retaliate?

Almost never. Boards and assessors don't have time to retaliate, and most jurisdictions explicitly prohibit raising values during the appeal process. The worst case in 99% of appeals is "your assessment stays the same."

How long does the appeal take?

DIY: 5–15 hours including evidence gathering, form filing, and hearing attendance. Contingency-service: 30 minutes to sign up and submit basic info. Time from filing to decision: 30 days to 6 months depending on jurisdiction backlog.

Can I appeal every year?

Yes — and many homeowners do, especially in annual-reassessment states like Texas. Once you've built your evidence file, refreshing it yearly is straightforward.

What happens after I win?

Your assessed value is updated. The savings flow through to your next tax bill (sometimes the current bill if the timing works out, or the next). If you've already paid a higher bill, most jurisdictions issue a refund or credit on the next bill.

Do I need to attend the hearing in person?

Increasingly no. Many jurisdictions now hold hearings by phone or video. Texas, Florida, and California have all moved to remote options for most residential cases. Confirm with your local board.

If my appeal is denied, can I escalate?

Yes. Most states have a multi-tier process: informal review → board hearing → state-level tax court or commission → judicial review. Each tier is more costly but available for high-stakes cases.

Should I use a contingency service or DIY?

DIY if you have 5–15 hours and a clear case (good comps, condition issues, or record errors). Contingency service if your time is more valuable than the year-1 fee, or if you've never been through the process and want someone else to handle the paperwork. Either way, filing is usually worth it.

Last reviewed Sources & methodology