What Assessors Care About (And What They Don't)
You can spend hours assembling a property tax appeal, but if you aim at the wrong target, you miss. Assessors work inside rules that reward certain evidence and shrug at the rest. Knowing which is which is the difference between a serious review and a quick pass. (New to appeals? Start with our Appeal 101 guide for the fundamentals.)
This guide tightens the advice, corrects a few common myths, and gives you a playbook that mirrors how assessors and appeals boards actually evaluate evidence.
What Assessors Care About: The Core Three
There are three categories of evidence that reliably move the needle.
1) Credible Comparable Sales
What it is Closed sales of truly similar properties that bracket your valuation date and support a lower market value. (For a complete deep-dive on finding and adjusting comps, see our guide to comparable sales.)
Why it matters
Market value is determined by what informed buyers and sellers agree to pay under typical conditions. That is the professional standard used in assessment practice. Mass appraisal models are calibrated to real, verified sales. Speak their language and you get traction.
What makes a comp credible
| Quality | What assessors look for |
|---|---|
| Timing | Sales closest to the valuation date carry the most weight. Some states limit how far after the date you can go. In California, boards cannot consider sales more than 90 days after the lien/valuation date. |
| Location | Same neighborhood or competitive market area. In dense urban areas that can mean a few blocks; in rural areas you may need a wider radius. |
| Similarity | Similar living area, age, quality, lot influences, and condition. Use adjustments that follow recognized appraisal methods. |
| Transaction type | Arms-length sales are preferred. Distressed sales can be used only when they reflect typical market behavior and are properly verified. |
| Verification | Sale details verifiable via public records, MLS, or assessor data. Avoid hearsay. |
Pro tip Do not just average unadjusted prices. Adjust for meaningful differences and tie your opinion of value to the adjusted indications around the valuation date. Appeals boards expect adjustments consistent with accepted methods.
What is not a comp
Asking prices and active listings should be used only as limited context, not primary evidence. Closed sales rule. Sales far outside the valuation window or market area do not qualify. Drastically dissimilar property types cannot be used as comparables.
2) Verifiable Property Condition
Mass appraisal models typically assume average condition unless you give them a reason not to. When documented condition issues reduce your property's market value below what the assessor's model assumes, credible photo sets, contractor estimates, and inspection reports show the market would pay less.
The key is being specific. Provide clear, dated photos of the issue—not just wide shots—and add at least one written estimate for big-ticket items. Then explain how buyers in your market actually react. Cost to cure is not automatically dollar-for-dollar value loss, but it supports a lower position within the comp range.
End-of-life roofs, significant HVAC or electrical issues, foundation problems, and drainage or pooling are the high-impact examples. Those are market-relevant and hard to hand-wave away.
3) Consistent, Accurate Data
Appeals boards weigh credibility above almost everything else. Internal contradictions and math errors sink cases that would otherwise win, so your appeal needs to tell a single, coherent story with precise facts that match public records or credibly correct them. When you present solid evidence, the risk of an unfavorable outcome is minimal—we cover this concern in detail in our guide on appeal risks.
That means maintaining the same opinion of value throughout and making sure your math ties. Your parcel number, address, and square footage should match the record—or if you're correcting them, provide clear documentation. Every comp needs a source link or citation the reviewer can verify fast.
Important Corrections and Clarifications
Anchor to the valuation date, not "the last 6-12 months"
"Recent" is only meaningful relative to your valuation date. Many jurisdictions allow older sales before the date but restrict how far after you can go. California is explicit: no sales more than 90 days after the lien/valuation date. Always check your state's rule.
Online estimates are not persuasive evidence
Automated valuations like Zestimates are not appraisals. Tribunals have found them non-probative as primary evidence. Use real, verified sales. (We debunk this and other misconceptions in our appeal myths guide.)
Distressed sales are not automatically banned
Short sales or REOs may be valid if they reflect typical buyer behavior in your market and are properly verified and adjusted. Blanket exclusion is not best practice.
For rentals or multi-unit property, bring income evidence
For income-producing property, assessors consider the income approach alongside sales and cost. Rent rolls, trailing 12s, stabilized expenses, and market-supported cap rates are persuasive.
What Assessors Do Not Care About
These points regularly appear in appeals and regularly flop.
"I cannot afford this tax increase." Appeals boards determine value, not your ability to pay or your tax rate. Tax rate and affordability arguments are out of scope. If affordability is the real issue, look for local relief programs; do not make that the centerpiece of a value appeal.
"My taxes went up too much." Same problem. The question is whether the assessed value matches market evidence for the valuation date. Show that it does not, or that your assessment is unequal compared with similar properties where that remedy exists. In Texas, for example, you can protest unequal appraisal under Tax Code 41.43.
"Zillow says my home is worth less." See above—and our myths article for why this approach consistently fails. Bring verified closed sales and adjustments, not AVM screenshots.
The Priority Matrix: Spend Time Where It Pays
| Evidence type | Time to spend | Why |
|---|---|---|
| Comparable sales research | 40% | Highest impact when tied to the valuation date and properly adjusted. |
| Property record verification | 20% | Correcting square footage or use-type errors can win an appeal by itself. |
| Condition documentation | 20% | Moves you to the lower end of the comp range with proof. |
| Write a concise summary | 15% | Make the reviewer's job easy and your math transparent. |
| Fancy formatting | 5% | Clean is good. Glitter is noise. |
How Assessors Review Your Appeal
While every office differs, the flow is consistent. First, the initial scan checks whether there is a clear opinion of value, tied to the valuation date, with verifiable comps. Second, the evidence review examines whether the comps are credible and adjusted, whether there are factual errors in the record you've documented, and whether the condition case is specific and supported. Third, verification confirms your work. They will pull the same sales in county systems, check property cards, and spot-check your math. Counties process thousands of appeals per year, so clarity and verifiability win. (Wondering whether to start with an informal review or formal appeal? See our comparison guide.)
Real-World Examples
Example 1: The clean comp package
Assessment: $525,000 What worked: Four closed sales bracketing January 1, with simple, cited adjustments for living area and renovation level. Short note that the subject's original kitchen places it at the low end of the range. Outcome: Reduction to a value supported by the adjusted comp range.
Why it works: verifiable sales near the valuation date plus specific condition context.
Example 2: The AVM appeal
Assessment: $450,000 What failed: A five-page narrative on tax burden plus a Zestimate printout. No closed sales or adjustments. Outcome: Denied. AVMs are not probative as primary evidence.
Example 3: The record-card fix
Assessment: $385,000 What worked: Submitted a prior appraisal and floor plan showing the assessor counted non-living space as GLA. Outcome: Reduced based on a corrected fact pattern. Boards cannot ignore documented, objective errors.
The Bottom Line
Assessors and appeals boards care about three things. First, sales evidence that is verified, adjusted, and near the valuation date. Second, property facts that correct the record or substantiate below-average condition. Third, credibility through consistent data and methods recognized in appraisal practice.
They do not care about your tax rate or hardship. Bring market evidence.
Want to skip the guesswork? AppealArc saves you time by building evidence-based appeals with verified comparable sales, record-card audits, and tidy, board-ready packets.
This article is general information, not legal or tax advice. Always check your local rules and deadlines.