Rob Hartley
Founder, AppealDesk · February 13, 2026
Understanding Your Property Assessment Notice: What Every Homeowner Should Know
Updated February 2026 · 10 min read
The short version: Your property assessment notice is the single most important document in the property tax process. It tells you what the county thinks your home is worth, and it starts the clock on your appeal deadline. Most homeowners toss it in a drawer. That mistake can cost hundreds — or thousands — of dollars every year. This guide explains what the notice is, how to read every line of it, and what to do if the numbers don't look right.
What Is a Property Assessment Notice?
A property assessment notice is an official document from your county or municipal assessor that states the government's estimate of your property's value. Think of it as a report card for your home — except instead of grades, it shows dollar amounts. And instead of affecting your GPA, it directly determines how much you pay in property taxes.
This is not your tax bill. That's a critical distinction most homeowners miss. The assessment notice tells you what the county thinks your home is worth. The assessed value on this notice is then multiplied by your local tax rate (minus any exemptions) to produce the tax bill you eventually receive. The notice comes first. The bill comes later.
The reason this document matters so much: the deadline to challenge your property's value is tied to the assessment notice, not the tax bill. In most states, once the appeal window closes, you're locked into that assessed value for the entire tax year — or longer if your state uses multi-year reassessment cycles. By the time you see the actual dollar amount you owe on the tax bill, it's usually too late to do anything about it.
When Does It Arrive?
The timing varies significantly by state and even by county within a state. Most assessment notices are mailed between January and June, but there are notable outliers:
- Texas: Notices of Appraised Value arrive in April (with a May 15 protest deadline)
- Florida: TRIM notices arrive in mid-August (with just 25 days to petition)
- New York: Tentative assessment rolls are published in May (Grievance Day is the 4th Tuesday)
- Illinois (Cook County): Change in Assessment notices arrive on a township-by-township schedule
- California: Regular notices arrive in summer; supplemental notices can arrive any time after a sale or new construction
If you're not sure when your notice typically arrives, check your county assessor's website or call their office. Some counties also publish this information on your state's appeal page.
Why Most Homeowners Ignore It (And Why That's Costly)
According to the National Taxpayers Union Foundation, fewer than 5% of homeowners ever appeal their property assessment. The other 95% fall into three camps: those who never open the envelope, those who glance at it and assume the county must be right, and those who intend to look into it but never get around to it before the deadline passes.
Meanwhile, research from the National Taxpayers Union Foundation estimates that 30–60% of all properties in the U.S. are overassessed. That means the county thinks your home is worth more than it actually is, and you're paying taxes on a number that doesn't reflect reality. Homeowners who do appeal win reductions 40–60% of the time, depending on the jurisdiction.
The assessment notice is your starting point. If you don't read it, you can't catch errors. If you don't catch errors, you can't appeal. And if you don't appeal, you pay whatever the county says — year after year.
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Anatomy of an Assessment Notice: How to Read Every Line
Assessment notices look different in every county, but they all contain the same core information. Here's what to look for and what each section means.
1. Property Identification
At the top of every notice, you'll find your parcel number (also called a PIN, APN, or tax ID), your property address, and the legal description. The parcel number is your property's unique identifier in the county's system — you'll need it if you file an appeal. Double-check that the address matches your actual property. Errors here are rare but not unheard of, and they can mean you're looking at a notice for the wrong parcel entirely.
2. Land Value vs. Improvement Value
Most assessment notices break your property's total value into two components: the land value (what the lot itself is worth, as if it were vacant) and the improvement value (the value of the structures on it — your house, garage, shed, pool, etc.). These two numbers add up to your total assessed value.
Why this split matters: if your land value seems disproportionately high relative to your neighbors' lots, that's a potential appeal argument. Similarly, if the improvement value seems inflated, it may indicate the assessor is using incorrect property characteristics — wrong square footage, extra rooms that don't exist, or a condition rating that doesn't reflect your home's actual state.
3. Previous Assessed Value vs. Current Assessed Value
Your notice will show both last year's assessed value and this year's assessed value. This is the single most important comparison on the entire document. A significant increase — particularly one exceeding 10–15% — is a red flag that warrants closer investigation.
Some states cap annual assessment increases for homesteaded properties. Texas limits increases to 10% per year (with additional limits for school taxes at 20% beginning in 2024). California's Prop 13 caps increases at 2% annually. Florida's Save Our Homes provision caps homesteaded properties at 3% or CPI, whichever is lower. If your increase exceeds your state's cap, something may be wrong with the calculation.
4. Assessment Ratio
Not every state assesses property at 100% of market value. As documented by the Lincoln Institute of Land Policy, many states use an assessment ratio — a percentage of market value that becomes the taxable value. For example:
- South Carolina: 4% for owner-occupied residential (one of the lowest in the country)
- Georgia: 40% of fair market value
- Utah: 55% for residential property
- Ohio: 35% of market value
- Illinois (Cook County): 10% for residential under $250,000
- California, Texas, Florida: 100% of market value (no ratio applied)
This matters because you need to compare apples to apples. If your state assesses at 40% and your assessed value is $160,000, the county is saying your home's market value is $400,000 ($160,000 ÷ 0.40). That's the number you compare to recent sales — not the $160,000 assessed value.
5. Estimated Tax Liability and Tax Rate
Some notices include an estimated tax amount or the tax rate (expressed as a millage rate, a dollar amount per $100 of assessed value, or a percentage). This gives you a rough idea of what your eventual tax bill will be, though the final bill may differ once exemptions and special assessments are applied.
Florida's TRIM notice is particularly helpful here — it actually shows you the proposed millage rates from each taxing authority (school board, county, city, special districts) and the dollar impact of each, which is why it's called a “Truth in Millage” notice.
6. Deadline and Appeal Instructions
Almost every assessment notice includes the deadline to file an appeal and at least basic instructions on how to do so. In many states, the appeal deadline is printed directly on the notice. In others, it references a date or a number of days from the mailing date.
Write this date down immediately. Put it in your calendar with a reminder two weeks before. This is not a date you can afford to miss. For a full breakdown of deadlines in all 50 states, see our complete 2026 appeal deadline calendar.
Assessment Notice vs. Tax Bill: Key Differences
Homeowners frequently confuse the assessment notice with the tax bill, or assume they're the same document. They're not. Understanding the difference is essential because the action you need to take — and the urgency of that action — is completely different for each.
| Assessment Notice | Tax Bill | |
|---|---|---|
| What it tells you | What the county thinks your home is worth | What you owe in property taxes |
| Formula | Market value × assessment ratio = assessed value | Assessed value × tax rate − exemptions = tax owed |
| When it arrives | Typically spring/summer (varies by state) | Typically fall/winter |
| Can you challenge it? | Yes — within the stated deadline | Usually too late by this point |
| Action required | Review values, note deadline, decide whether to appeal | Pay by due date to avoid penalties |
The most common — and most expensive — mistake homeowners make is waiting for the tax bill to see how much they owe, then deciding the amount is too high, and only then looking into an appeal. By that point, the assessment notice deadline has long passed. The appeal window might have closed weeks or even months ago.
The rule of thumb: Act on the notice, not the bill. The notice is where you have leverage. The bill is just math.
Red Flags on Your Assessment Notice: Signs of Overassessment
Not every high assessment is wrong. Home values do increase, and sometimes the county's number is perfectly accurate. But certain patterns on your notice are strong indicators that something is off. Here's what to look for:
Your Assessment Jumped More Than 10–15% Year Over Year
Unless you made major improvements (added a room, renovated a kitchen, built a pool) or your county conducted a full revaluation, a spike of 10–15% or more deserves scrutiny. Even in a strong real estate market, assessment increases that outpace actual neighborhood sales are a sign that the assessor's mass appraisal model may have overshot your property.
Your Assessment Is Higher Than Recent Comparable Sales
This is the most reliable indicator of overassessment. If similar homes in your neighborhood (same size, age, condition, lot size) have sold recently for less than what the county says your home is worth, you likely have a strong case for an appeal. This is exactly the kind of evidence that review boards respond to — comparable sales are the foundation of any successful appeal.
Your Property Details Are Wrong
Check the square footage, lot size, bedroom count, bathroom count, year built, and any other physical characteristics listed on the notice. Assessors work from property records that may be outdated or contain data-entry errors. A finished basement counted as living space when it's actually unfinished, an extra bathroom that doesn't exist, or incorrect square footage can inflate your value significantly. Factual errors are the easiest type of appeal to win because the correction is objective — the data is simply wrong.
The Assessment Ratio Doesn't Match Your State's Statutory Ratio
If your state uses an assessment ratio (e.g., 40% in Georgia, 35% in Ohio), divide your assessed value by that ratio to find the implied market value. If the implied market value is significantly higher than what comparable homes are selling for, the assessment is too high. This calculation is the single most powerful tool homeowners have for evaluating whether their assessment is fair.
The Condition Code Doesn't Reflect Reality
Many assessors assign a condition code to your property — typically on a scale from “poor” to “excellent.” If your home is rated “good” or “excellent” but actually has deferred maintenance, an aging roof, outdated systems, or other condition issues, the rating is inflating your value. This is particularly common in areas where assessors haven't visited properties in person for years and rely on older inspection data.
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What to Do When You Receive Your Assessment Notice
Don't toss it in a drawer. Don't assume the county is right. And don't wait until tax bills come out. Here is a five-step process you can follow the same day the notice arrives.
If you want to skip the research, you can enter your address on AppealDesk and we'll pull your current assessment, compare it to recent sales, and build a complete evidence packet ready to file — for a flat $49.
State-Specific Notice Names and Terminology
One reason homeowners overlook their assessment notice is that it doesn't always say “assessment notice” on the envelope. Different states use different names for the same document, which can cause confusion — especially for homeowners who have moved from one state to another.
| State | What They Call It | Key Detail |
|---|---|---|
| Texas | “Notice of Appraised Value” | Sent by the County Appraisal District; challenge is called a “protest” |
| Florida | “TRIM Notice” (Truth in Millage) | Uniquely detailed — shows proposed taxes from every taxing authority |
| New York | “Tentative Assessment Roll” | Published (not individually mailed in many towns); challenge is called a “grievance” |
| Illinois (Cook Co.) | “Change in Assessment Notice” | Mailed on a township-by-township schedule; triennial reassessment cycle |
| California | “Notice of Supplemental Assessment” | Triggered by change of ownership or new construction; Prop 13 limits routine increases to 2% |
| Georgia | “Notice of Assessment” or “Annual Notice of Assessment” | 45-day appeal window; assessed at 40% of fair market value |
| Ohio | “Notice of Valuation” | Sent in reappraisal and triennial update years; assessed at 35% of market value |
| New Jersey | “Assessment Notification Postcard” | Small postcard format; April 1 deadline (Jan 15 for 3 counties) |
| Colorado | “Notice of Valuation” (NOV) | Mailed by May 1; challenge is called an “objection”; 2-year cycle |
Regardless of what your state calls it, the underlying purpose is the same: the government is telling you what they think your property is worth, and giving you a limited window to disagree. If you receive a document from your county assessor or appraisal district that contains a dollar value for your property, treat it as your assessment notice and review it immediately.
For more on how your state handles the appeal process and what specific terminology they use, visit your state's appeal guide or check our guide on the best ways to lower your property taxes.
Common Mistakes Homeowners Make With Their Assessment Notice
Mistake #1: Assuming the County Is Always Right
County assessors use mass appraisal models that estimate thousands of property values at once. These models are good at getting close — but as the International Association of Assessing Officers (IAAO) acknowledges, they're not designed to be precise for individual properties. They can't account for your home's specific condition, unique layout, or the fact that your neighbor's house is on a quieter street. The assessment is an estimate, and estimates can be wrong.
Mistake #2: Confusing Assessed Value With Market Value
In states that use an assessment ratio, the assessed value on your notice is not what the county thinks your home is worth on the open market. It's a fraction of that amount. You need to divide by the ratio to get the implied market value before comparing to sales data. Skipping this step leads homeowners to think their assessment is reasonable when it may actually imply an inflated market value.
Mistake #3: Waiting for the Tax Bill
This is the costliest mistake of all. The tax bill arrives after the assessment has been finalized and the appeal deadline has passed. If you see a high tax bill and think “I should have appealed,” you're right — but the time to act was weeks or months earlier when the assessment notice arrived.
Mistake #4: Not Checking the Property Description
Many homeowners focus exclusively on the dollar values and skip the property details section. But errors in square footage, lot size, bedroom count, bathroom count, or condition rating are surprisingly common — and they directly inflate the assessed value. An extra 200 square feet in the assessor's records could mean hundreds of dollars in extra taxes every year.
Mistake #5: Thinking the Process Is Too Complicated
At the initial level, most property tax appeals are straightforward. You fill out a form, attach evidence (comparable sales, photos, a description of errors), and submit it by the deadline. You don't need a lawyer. You don't need an appraiser. You just need to show that the county's number is too high. For more on the process, see our step-by-step appeal guide.
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Frequently Asked Questions
What is a property assessment notice?
What is the difference between an assessment notice and a property tax bill?
How do I know if my assessment notice is wrong?
When do property assessment notices arrive?
What should I do when I receive my assessment notice?
Can I appeal my property assessment if I already received my tax bill?
The Bottom Line
Your property assessment notice is not just another piece of government mail. It's the document that determines how much you pay in property taxes — and it's the only point in the process where you have the power to challenge that number.
When it arrives, open it immediately. Check the property details for errors. Calculate the implied market value. Compare it to what similar homes in your neighborhood actually sold for. And if the numbers don't add up, note the deadline and take action.
The appeal process is more accessible than most homeowners realize. You don't need a lawyer or a professional appraiser — you need the right evidence. Comparable sales, accurate property data, and a clear argument that the county's number is too high. That's what review boards respond to. And that's exactly what AppealDesk builds for you.
The county assessed your property. Now it's your turn to assess the county's work. If you're a new homeowner receiving your first assessment notice, our first-time homebuyer's guide to property taxes covers everything from escrow to homestead exemptions. Once you have your numbers, use our savings calculator to see if your assessment is too high.