Property Tax Appeal Glossary: Key Terms Explained

Property tax appeal glossary: the terms you need to know

A property tax appeal is the formal process of asking your local taxing authority to correct the assessed value of your home when you believe it is too high, and understanding the vocabulary on your assessment notice is the first step to a successful challenge. This glossary defines the core terms — assessed value, market value, the assessment ratio, exemptions, the appeal deadline, and the evidence you use to prove your case — in plain language that applies to homeowners in any U.S. state. Because rates, deadlines, and procedures vary widely by jurisdiction, always confirm the specific numbers and dates on your own assessment notice and your county assessor's website.

Property tax terminology is not standardized nationwide. The same concept may be called an "assessor" in one place and an "appraisal district" in another, and a "Board of Review" versus a "Board of Equalization" versus an "Appraisal Review Board" depending on where you live. This guide focuses on the concepts, which travel across state lines, and flags where the label or the mechanics commonly differ.

Core value terms

Assessed value

The dollar figure your local government places on your property for tax purposes. Your tax bill is generally calculated from this number, not from what you paid or what your home would sell for today. In many jurisdictions the assessed value is only a fraction of market value (see assessment ratio). This is the number most appeals are actually fighting about.

Market value (fair market value)

The price your property would likely sell for in an open, arm's-length transaction between a willing buyer and a willing seller, with neither under pressure. Assessors estimate this as of a specific date. Many appeals argue that the assessor's estimate of market value is higher than the home's true market value.

Appraised value

The value determined by a professional appraiser or, in some states, the term the taxing authority uses for its own estimate of market value before any ratio or exemption is applied. Terminology overlaps with "market value" and "assessed value" depending on the state, so read your notice carefully to see which figure drives your bill.

Assessment ratio (assessment level / assessment rate)

The percentage of market value that becomes the assessed value. Where a ratio is used, assessed value equals market value multiplied by the ratio. If your jurisdiction publishes a target ratio, comparing it to your own assessed-to-market ratio can reveal whether you are over-assessed relative to similar homes.

Taxable value

The amount left after exemptions and any assessment caps are subtracted from the assessed value. This is the figure the tax rate is actually applied to. Taxable value can be lower than assessed value if you qualify for exemptions or caps.

How the bill is calculated

Millage rate (mill levy / tax rate)

The rate used to calculate your tax. A "mill" traditionally represents one-tenth of one cent of tax per dollar of taxable value, though jurisdictions express the rate in different ways. Rates are set by the taxing bodies that your property funds and change from year to year — do not rely on a rate you saw in a prior year or in another county.

Levy

The total amount of revenue a taxing body decides to raise from property taxes. The levy, spread across all taxable property, helps determine the rate. You generally cannot appeal the levy or the rate; you appeal your property's value.

Taxing authority / taxing district

The government entities that collect property tax from your parcel — which may include a county, city, school district, and special districts. A single bill often funds several districts.

Parcel / parcel number (APN)

Your property's unique identifier in the county's records (sometimes called an Assessor's Parcel Number). You will need it for any appeal filing and to look up comparable properties.

The appeal process terms

Assessment notice (notice of valuation / notice of assessment)

The document your assessor sends stating your property's value for the year. It typically starts the clock on your right to appeal. Read it as soon as it arrives — the window to respond is often short and is stated on the notice itself.

Appeal deadline (protest deadline)

The last date to file a challenge. This varies significantly by jurisdiction and can be tied to the date on your notice rather than a fixed calendar date. Missing it usually means waiting until the next year. Confirm your exact deadline on your notice or county website; do not assume a date from any general article.

Informal review (informal appeal)

An optional first step in many areas where you discuss the value directly with the assessor's office before a formal hearing. It is often faster and lower-stakes, and it sometimes resolves the issue without a hearing.

Formal appeal / hearing

A structured review before an independent body. Depending on the state, this body may be called a Board of Review, Board of Equalization, Assessment Appeals Board, or Appraisal Review Board. You present evidence; the assessor may respond; the board decides.

Board of Equalization / Board of Review / Appraisal Review Board

Different names for the local panels that hear property tax appeals. Their job is to ensure assessments are fair and uniform. The specific name, composition, and rules depend on your jurisdiction.

Burden of proof

The responsibility to demonstrate that the assessment is wrong. In many jurisdictions the homeowner carries this burden and must show, with evidence, that the assessed value exceeds what it should be.

Comparable sales (comps)

Recent sales of similar properties — similar in size, age, condition, location, and features — used to estimate what your home is worth. Strong, recent, nearby comps are the most common and persuasive evidence in a residential appeal.

Uniformity / equalization

The principle that similar properties should be assessed similarly. An appeal can argue that your home is assessed higher than comparable neighboring homes, even if the assessor's market-value estimate seems defensible on its own.

Reassessment

The process of updating property values, either on a regular cycle or after a triggering event such as a sale or new construction. A reassessment is often what prompts a homeowner to appeal.

Relief and reduction terms

Exemption

A provision that reduces your taxable value or tax if you qualify. Common categories include homestead (owner-occupied primary residence), senior, veteran, and disability exemptions. Eligibility rules and amounts are set locally — check what your jurisdiction offers, because missing an exemption you qualify for is a common and avoidable overpayment.

Homestead exemption

A reduction available to owners who occupy the property as their primary residence. Where offered, it can lower taxable value and, in some places, cap how fast assessed value can rise.

Assessment cap (value cap)

A limit on how much the assessed or taxable value can increase in a given period, often tied to a homestead. Caps can make your assessed value lag behind market value in rising markets.

Abatement

A temporary reduction or elimination of taxes, often tied to specific programs, property types, or improvements. Distinct from an exemption, which is usually ongoing.

How to use these terms in an appeal: a checklist

1. Read your assessment notice fully. Identify the assessed value, any assessment ratio, your taxable value, and — critically — your appeal deadline.
2. Confirm the deadline and process on your county assessor's or appraisal district's website. These are jurisdiction-specific and change.
3. Check whether the assessor's facts are correct. Square footage, lot size, number of rooms, and condition errors are common and easy to document.
4. Verify your exemptions. Confirm you are receiving every exemption you qualify for (homestead, senior, veteran, disability, etc.).
5. Gather comparable sales. Find recent sales of similar nearby homes that suggest a lower market value than your assessment implies.
6. Consider a uniformity argument. Compare your assessment to similar neighboring properties to see if you are assessed higher than your peers.
7. Decide informal vs. formal. Try an informal review first if your jurisdiction offers one.
8. Prepare your evidence packet and meet every deadline. Keep copies of everything you submit.

Factors that affect whether an appeal is worth filing

• Size of the potential reduction relative to the effort and any filing requirements.
• Quality of your evidence — recent, truly comparable sales matter most.
• Errors on record — factual mistakes about your property are often the strongest, simplest grounds.
• Local process and deadlines — a short window or complex hearing may affect your approach.
• Whether you qualify for missed exemptions, which may be correctable outside a value appeal.

Always base decisions on the actual figures on your notice and the rules published by your local taxing authority.