The number your county assessor assigns to your property is an educated estimate, not an authoritative appraisal. It's calculated by software that compares your home to recent sales of "comparable" properties, applies a statistical model, and spits out a value — usually without anyone ever stepping foot on your lot. Because the process is mass-produced, it produces errors. And because your tax bill is calculated directly from that value, those errors cost you money. Appealing is how you fix them.
Why appeals work
Published success rates for assessment appeals vary by jurisdiction, but most appraisal offices acknowledge that 30–60% of filed appeals result in some reduction. The reason isn't that most properties are wildly overvalued — it's that mass appraisal systematically produces outliers, and if you're one of them, pointing that out almost always gets some fix. The appraiser isn't arguing with you personally; they're correcting bad data.
The value of an appeal is easy to underestimate. Even a 5% reduction on a $400,000 home takes $20,000 off your tax base. At a 2% effective rate, that's $400/year. Hold that reduction for 10 years (most appeals hold until the next full reassessment cycle or major neighborhood change), and you've saved $4,000 on a single hour of paperwork.
What to gather before you file
A successful appeal needs evidence that your property is worth less than what the assessor says it is. The strongest evidence, in rough order of effectiveness:
- Recent sales of genuinely comparable homes in your neighborhood at lower prices than your appraised value. "Comparable" means similar square footage, similar lot size, similar age, similar condition. Three good comps beat ten weak ones.
- A recent purchase of your home at a price below the appraisal. If you bought the home 12 months ago for $380,000 and the appraiser values it at $420,000, that sale price is nearly ironclad evidence — the market said your home was worth $380,000.
- An independent appraisal done for a refinance or purchase showing a lower value.
- Photos of defects the assessor couldn't have seen from the street: foundation issues, flooding, roof damage, outdated kitchens/baths, deferred maintenance. Proof of expensive repairs needed.
- Errors in the appraiser's record: wrong square footage, wrong bedroom count, wrong lot size, wrong year built, missing info about a negative feature (busy road, flood zone, easement).
State-by-state: deadlines, forms, and process
Texas: file by May 15 (or 30 days after your notice)
Texas has arguably the most homeowner-friendly appeal process — the state actively encourages protests, and the system is well-oiled.
- Deadline: May 15 of the tax year, or 30 days after your Notice of Appraised Value is mailed, whichever is later.
- Form: Notice of Protest (Form 50-132) filed with your appraisal district.
- Process: most districts offer an informal meeting first — a brief sit-down with an appraiser where you present evidence and often walk out with a reduction. Unresolved protests go to the Appraisal Review Board (ARB), a panel of trained citizens who hear formal evidence.
- Success rate: approximately half of Texas protests receive some reduction.
County pages with appeal contact info: Harris, Dallas, Tarrant, Travis, Bexar.
Florida: 25 days after TRIM notices
- Deadline: 25 days after Truth in Millage (TRIM) notices are mailed (mid-August).
- Form: Petition to the Value Adjustment Board (VAB). $15 filing fee in most counties.
- Process: informal review with the property appraiser first, then VAB hearings through fall. If the VAB denies, you can take the case to circuit court.
- Heads up: Florida's Save Our Homes cap means that if you're a long-term homesteader, your assessed value is often far below market — in that case you have nothing to appeal. Appeal when assessed value approaches or exceeds market value (newer homesteads, recent buyers, hot markets).
County pages: Miami-Dade, Broward, Orange, Hillsborough.
Indiana: 45 days after your Form 11
- Deadline: 45 days from the date on your Form 11 (Notice of Assessment), which typically arrives in spring.
- Form: Form 130 (Taxpayer's Notice to Initiate an Appeal), filed with your township assessor.
- Process: informal resolution with the assessor first; unresolved appeals go to the county Property Tax Assessment Board of Appeals (PTABOA). Beyond that, the Indiana Board of Tax Review, then Tax Court.
- Unique twist: Indiana's 1% circuit breaker means that for most homesteads in high-rate districts, the tax is already capped at 1% of gross AV — so reducing your AV always reduces your bill proportionally, whether you hit the cap or not. This makes appeals in Indiana more consistently valuable than in states where caps don't apply uniformly.
Illinois: Board of Review (varies by county)
- Deadline: varies by county and township — typically 30–60 days after reassessment notices are mailed.
- Process in Cook County: first appeal to the Cook County Assessor within 30 days of the township's reassessment notice; if unsatisfied, appeal to the Cook County Board of Review. Beyond that, the Illinois Property Tax Appeal Board (PTAB) or circuit court.
- Process elsewhere: township assessor first, then County Board of Review, then PTAB.
- Triennial reassessment: Cook County reassesses property every three years on rotating regions — North suburbs, South suburbs, and the City of Chicago. Know which year your township is up.
Tennessee: County Board of Equalization in June
- Deadline: typically within 45 days of the appraisal notice. Counties vary; some set firm deadlines in May.
- Process: request an informal review with the assessor first. If unsatisfied, file with the County Board of Equalization, which meets each June. Appeal further to the State Board of Equalization and ultimately chancery court.
- Reappraisal cycles: Tennessee counties reappraise every 4, 5, or 6 years. Appeals are most effective during a reappraisal year (newly changed values) but still work in off-years if you have strong evidence of error.
Arizona: 60 days after Notice of Value
- Deadline: 60 days from the date of your Notice of Value, mailed by March 1.
- Process: appeal to the county assessor first. If unresolved, escalate to the County Board of Equalization (or State Board in larger counties), then Tax Court.
- High-leverage appeal: Arizona's single most valuable appeal opportunity is a Rule B valuation on newly constructed property. Because the LPV established in year one becomes the locked base value under Prop 117, reducing it in year one saves money every year thereafter. This is sometimes called the "once in a lifetime" appeal.
Major Arizona county: Maricopa.
Should you hire a professional?
Professional property tax protest firms operate in most states — typically charging a contingency fee (25–50% of the first year's savings). They're most useful in jurisdictions where evidence-gathering is genuinely complex (commercial property, very high-value homes, unusual parcels) or when you simply don't have time. For a typical single-family home with a clear case for reduction, a well-prepared homeowner filing directly has just about the same success rate as a professional firm — and keeps all the savings.
If you do hire a firm, ask:
- Is the fee capped at your first year's savings or does it recur?
- Do they charge a minimum or flat fee regardless of outcome?
- What's their success rate on properties similar to yours in your specific appraisal district?
Worth remembering
Appeals rarely reduce your value dramatically — 5–15% is a common range. But because that reduction compounds over years, and because the process is essentially free (time + evidence), it's one of the highest-ROI tasks available to a homeowner. If you haven't protested in 5+ years, there's a good chance your assessment has drifted above market.
Related: How to read your property tax bill · Homestead exemptions explained · Find your county page.