Top 10 Appeal Myths, Busted
Property tax appeals collect folklore like lint on a cashmere sweater. Neighbors swap war stories, forums amplify half truths, and that one friend-of-a-friend swears he "knew a guy." Time to clear the air.
Below are the 10 myths we see most, what is actually true, and how it affects your appeal strategy. (New to appeals? Start with our Appeal 101 guide to understand the fundamentals first.)
Myth 1: "My Zillow Zestimate is valid evidence"
The myth: Print your Zestimate, show it is lower than your assessed value, win.
Reality: Online AVMs are not appraisals and rarely persuade assessors or appeals boards. Zillow states plainly the Zestimate is not an appraisal and should not be used in place of one. Zillow also reports nationwide median error rates that vary by status, with lower error for on-market homes and higher for off-market homes. Use AVMs to find comps, then present the actual closed sales.
What to do instead: Pull recent, arm's length sales of truly similar properties and bring contracts, closing statements, or a licensed appraisal when available. Los Angeles County's hearing guide explains comparable sales rules and timing windows, which most jurisdictions mirror. Our comparable sales guide walks you through the complete process.
Myth 2: "Home improvements always raise taxes immediately"
The myth: Remodel today, tax bill spikes tomorrow.
Reality: Improvements can lead to reassessment, but timing and impact depend on permits, completion dates, state rules, and whether your jurisdiction issues supplemental assessments. In California, completed new construction is generally added as a supplemental assessment; not every permit results in a higher assessment, and many assessors review thousands of permits with less than half leading to increases.
How assessors discover changes: Building permits are routinely forwarded to assessors; further discovery comes from sales, field checks, and aerial imagery. Bottom line: follow the law and pull permits, but do not assume a next-year automatic tax jump.
Myth 3: "Appealing will get me audited by the IRS"
The myth: File a local property appeal, trigger a federal audit.
Reality: Local property assessments and IRS audits are unrelated processes. The IRS selects returns through computer screening and other federal criteria, not because you challenged a county valuation.
Myth 4: "I need a lawyer or consultant to have a chance"
The myth: DIY guarantees a loss.
Reality: Many residential owners win reductions with organized evidence and a clear narrative. For example, Cook County data show a meaningful share of homeowner appeals succeed, and the county offers multiple pathways to file. Professional help is useful for complex or high-value cases, but it is not mandatory to be effective.
Pro tip: LA County even runs free seminars on preparing evidence and hearings. That kind of taxpayer education exists in many metros.
Myth 5: "If I appeal, they will increase my assessment"
The myth: Appealing is a trap.
Reality: Most boards can lawfully reduce, sustain, or increase a value based on the evidence. California county materials, for instance, explicitly warn that the board may raise or lower the value after hearing. In practice, increases are uncommon, but they are possible, so present only support for a lower opinion of value. We cover this concern thoroughly in our guide on appeal risks.
Risk management: Stick to closed sales that support your number, avoid volunteering unrelated upgrades, and come prepared with photos and condition notes.
Myth 6: "Comps must be on my street to count"
The myth: If it is not next door, it is irrelevant.
Reality: The best comps are in the same market area and school district, share similar age, size, style, and condition, and sold near the valuation date. Many boards accept sales before the lien date and up to a limited period after. LA County's guide caps comps to no more than 90 days after the valuation date for common residential appeals.
Rule of thumb: In dense urban areas, a 0.5 to 1 mile radius often yields strong comps. In rural markets, expand the radius but match property type and amenities tightly. For detailed guidance on finding and adjusting comps, see our comparable sales guide.
Myth 7: "I only get one shot to appeal"
The myth: Lose once, lose forever.
Reality: You typically get one appeal per assessment year, and you can appeal again the next year if market evidence changes. Many counties reassess on cycles, but owner appeals can be annual. Check your local filing window. Understanding whether to pursue an informal or formal appeal helps you use each opportunity strategically.
Myth 8: "My assessment equals my tax bill"
The myth: Assessed value of 500,000 means 500,000 in taxes.
Reality: Your bill is your taxable assessment multiplied by the total local rate, often expressed in mills, adjusted by exemptions. States differ on assessment ratios and caps, but the core formula is consistent: Taxes owed = taxable assessment × tax rate.
Why it matters: A 50,000 reduction saves 500 per year at a 1 percent rate and 1,000 per year at a 2 percent rate. Know your rate to estimate savings credibly.
Myth 9: "Assessors visit every property every year"
The myth: Annual walk-throughs are standard.
Reality: Modern assessment relies on mass appraisal. Physical reviews are periodic, not annual. IAAO guidance cites inspection cycles on the order of years, with jurisdictions supplementing field work with permits, sales, imagery, and ratio studies to calibrate models.
Implication for appeals: If your property has condition issues the assessor has not seen, photos and contractor estimates can be decisive.
Myth 10: "Appeals never work"
The myth: Counties never reduce because they need revenue.
Reality: Appeals succeed regularly, though rates vary by place and year. In Cook County, a large sample year showed roughly four in ten homeowner appeals winning some relief. The takeaway is simple: well-supported evidence gets results.
Quick hits on two bonus myths
"My listing price proves market value." List prices are hopes, not evidence. Boards want closed, arm's length sales—understanding what assessors care about helps you focus on the right evidence.
"I need a full appraisal to appeal." A licensed appraisal helps, but a solid comparable sales package with photos and adjustments is often sufficient for residential appeals. Many boards publish checklists for exactly this.
Your three step action plan
- Confirm the rules for your county and state. Look up the appeal window, valuation date, and comparable sale timing rules. Many counties document these in plain English.
- Build evidence that boards actually accept. Closed sales near the valuation date, condition photos, correction of record errors, and appraisals when the numbers are large.
- Model your savings credibly. Apply your local tax rate to the proposed reduction so you know if the juice is worth the squeeze.
Bottom line
Good appeals are not about internet estimates or folklore. They are about local rules, recent closed comps, credible adjustments, and clear presentation. The system is bureaucratic, not rigged. Show up with evidence and you give yourself a real shot. For more on what evidence actually works, see our guide on what assessors care about.
Want county-specific guidance and a comps package that boards actually accept? AppealArc helps you pull defensible sales, check your property record, and generate a hearing-ready packet in minutes.