Topic guide · updated 2026-08-02
Appealing a property tax assessment
An assessment appeal is an evidence argument with a hard deadline. This explains how to tell whether a property is over-assessed, what a reduction is actually worth, what the three routes to filing cost, and why the deadline wording matters more than the date.
Property tax is charged on a value somebody at the county assigned to your property. If that value is too high, the tax is too high, and every jurisdiction publishes a way to contest it.
The process is unusually tractable. It turns on evidence about value rather than legal argument, first-level filings are generally free, and the arithmetic is simple enough to check in a few minutes.
The part that catches people is the deadline — and specifically the wording of it, which is not always what a static table prints.
Working out whether you are over-assessed
Compare the assessed value against recent sales of genuinely similar nearby properties. If the assessment sits meaningfully above the median of those sales, that gap is the argument. Use the median rather than the average. Comparable sales are a small sample, and one unusual transaction — a teardown, a family transfer, a distressed sale — pulls an average a long way. Assessing offices reason in medians for the same reason. Where a state assesses at a fraction of market value rather than the whole, divide the assessed figure by that ratio before comparing, or you are measuring a slice against a whole and will see an over-assessment that is not there. A gap of a few percent is generally within tolerance. Valuation is approximate by design and authorities expect to be roughly rather than exactly right.
What a reduction is worth
Multiply the reduction in assessed value by your combined rate per hundred dollars of value — the form counties publish rates in — and you have the annual saving. That figure is worth calculating before deciding whether to spend a weekend on evidence, and worth calculating again before paying anyone to do it for you.
Three routes, and what each keeps you
You can file yourself, which costs nothing in most jurisdictions beyond your time and the evidence you gather. A flat-fee service prepares comparable-sales research and a filing for a published price. A contingency service takes a published share of the first year's saving and charges nothing if the appeal fails. Which is right depends entirely on your figures, which is why they are shown side by side. On a small reduction a contingency share is modest in absolute terms; on a large one it is not, and a flat fee overtakes it. We are not one of the three and do not file appeals — the comparison is arithmetic, not a recommendation.
The deadline, and why its wording matters
Every jurisdiction publishes a window, and the rule is often conditional rather than a fixed date. Texas sets the deadline as May 15 or thirty days after the notice was delivered, whichever is later. That means a notice arriving late moves the deadline outward — and a static table printing only 'May 15' tells some owners they have missed a window they still have. Many jurisdictions also set a separate, shorter window for exchanging evidence before the hearing, and most require the protest on their own form or through their portal rather than by letter alone.
What assessing authorities actually want
Comparable sales and documented condition problems. Recent arm's-length sales of similar properties carry the most weight. Distressed sales, family transfers and teardowns are routinely discounted, and including one weakens the rest of a list rather than lengthening it. Condition arguments need evidence — a dated photograph, a repair quote — rather than description. An appeal that arrives as an organised set of facts is materially easier to grant than one that arrives as a complaint.
Tools in this topic
Every calculator and explainer in this cluster, each built on verified figures with its official source linked.
Property Tax Appeal
Work out how far your assessment sits above comparable sales, what a reduction would save at your local rate, and what each of the three routes to it costs — filing yourself, a flat-fee service, or a contingency service. Every county deadline is cited to the authority that sets it.
Appeal Letter
Build a one-page notice of protest from your parcel number, the assessed value, the value you believe is correct, and your comparable sales. It states facts and requests a review — it makes no legal argument, and nothing you type leaves your browser.
Guides
Protest deadlines are rules, not dates
Many jurisdictions set the deadline for contesting an assessment as a condition rather than a calendar date — thirty days after notice, or a fixed date, whichever is later. A table printing only the fixed date sends some owners away too early.
What assessing authorities actually want to see
An assessment appeal is an evidence argument. Comparable sales and documented condition problems carry it; adjectives do not. This explains which comparables help, which ones weaken a list, and how to organise the rest.
Key terms
Frequently asked questions
In most jurisdictions a first-level review looks at whether the assessment is correct, which means it can in principle be revised in either direction. It is uncommon, but it is a real consideration if your assessment is already below what comparable properties sold for — which the calculator will tell you before you file.
Official sources for this topic
Every figure and rule referenced above is published by one of these agencies, and each of them — not this site — determines what is actually paid.
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