Build a Property Tax Appeal Packet From Your Own Numbers
An assessment is an opinion, not a measurement — and it can be tested. This takes your assessed value, a few comparable sales, and your tax rate, then prints how far over the comparables you are, what that gap costs you every year, and a dated checklist of the evidence an appeal board actually asks for, counted back from your filing deadline. Local only; your figures never leave the tab.
- Gap
- Assessed value against your comparables, as a percentage
- local
- What it replaces
- A hunch that the assessment 'feels high'
- $0.00
- Input
- Assessed value, comparables, tax rate, deadline
- no card
- Output
- A priced gap and a dated evidence checklist
- recomputed
What you pay otherwise
| Route | What you get | Cost |
|---|---|---|
| Appeal-prep service | Someone files what you could file yourself | $200–$500 |
| Not appealing | An over-assessment you pay every year it stands | recurring |
| Appealing with no comparables | A hearing you lose on evidence | the year lost |
| This page | The gap priced and the evidence dated | $0 |
The workflow
Enter the assessed value from the notice, not the market price
The assessment is the figure the tax is calculated on, and it is often below market value by design. Comparing your assessment to a sale price without accounting for the assessment ratio produces a gap that isn't real.
Use three to five genuinely comparable sales
Same neighbourhood, similar size and age, sold within the last year. One luxury renovation next door is not a comparable — it's an outlier, and an appeal board will discount the whole packet because of it.
Read the annual figure, not the percentage
A 12% over-assessment sounds abstract until it's priced at your tax rate. The annual number is what makes the effort worth it, and it's the figure that tells you whether an hour of prep pays for itself.
Work the checklist backwards from the filing deadline
Evidence gathering is what people run out of time for, not the filing itself. The checklist dates each step from your deadline so the appraisal request goes in early enough to actually arrive.
Worked example
Sample: assessed 412,000, 4 comparables, 1.18% rate Comparable average 368,500 Over-assessment 11.8% Excess value 43,500 Annual tax at stake 513.30 Filing deadline 2026-10-30 Uploaded nothing — computed in the tab
Numbers above are sample data produced by the tool's own pre-loaded example, run in the browser — not averages or measured benchmarks.
What breaks this
Comparing an assessed value to a market sale price without the assessment ratio invents a gap that isn't there. Using one uncomparable sale — bigger, renovated, or a distressed sale — undermines the whole packet. Waiting until the week of the deadline to request records; the checklist exists because evidence takes longer to gather than the filing takes to submit.
Try it now
An assessment of 412,000 against four comparables is loaded, showing an 11.8% gap. Remove the highest comparable and watch the gap widen.
Open the appeal packet →Go deeper: the printable notice
The packet is free forever. The $4 one-time tier adds:
- Printable notice — the gap, the comparables and the checklist on one sheet for the hearing — estimate: ~20 min saved reformatting before you file.
- Saved properties shelf — keep up to 4 assessments in this browser — estimate: ~15 min saved at next year's reassessment.
- Comparable table export — a clean comparison table you can attach — estimate: ~25 min saved building the exhibit by hand.