How long do I have to appeal my property tax assessment?

It varies by county, but the window is usually 30–60 days after the assessment notice is mailed, and in some places it's as short as two weeks. The deadline is printed on the notice. Missing it means waiting until next year, so put it on your calendar the day the notice arrives.

Can appealing raise my assessment?

In most jurisdictions, no — the assessor can only lower or leave it. A few states allow the board to raise an assessment on appeal if evidence shows it's too low, so check your county's rules. In practice this is rare, and if your evidence shows you're overassessed, there's little risk.

Do I need a lawyer or a property tax consultant?

Not for a residential appeal. Consultants typically charge 25–50% of the first year's savings and mostly do what this guide describes. If your home is unusually valuable or the case involves a legal question about classification or exemptions, an attorney may be worth it.

What's the difference between assessed value and market value?

Market value is what the home would sell for. Assessed value is what the county uses to calculate your tax, and it's often a fixed percentage of market value (the assessment ratio). Your appeal argues the county's opinion of market value is too high, so you need to know your area's ratio to compare correctly.

Should You Appeal Your Property Tax Assessment? Here's How to Decide (and Win)

Your county assessor values hundreds of thousands of homes using a computer model and a handful of appraisers. They don’t walk through your house. They don’t know about the cracked foundation, the busy road, or the fact that the “finished basement” on record has been a laundry room since 1998. Errors are common, and the system is set up so that the burden is on you to catch them.

The good news: residential appeals are designed for homeowners to do themselves, and a well-prepared one has a real chance of success. The National Taxpayers Union has estimated that 30–60% of homeowners who appeal win at least a partial reduction, yet fewer than 5% ever try.

Step 1: Decide whether you have a case (30 minutes)

Pull your assessment notice and check three things.

The facts on the property record card. Your county’s assessor website has a record for your parcel listing square footage, bedroom and bathroom count, lot size, garage, basement finish, and condition. Compare every line to reality. The most common errors:

Square footage that includes an unfinished basement, garage, or porch
Wrong bathroom count (a half bath recorded as a full)
“Finished” basement or attic that isn’t
Lot size or acreage that’s wrong
A pool, deck, or outbuilding that was removed
Condition rated “good” or “excellent” when the house has deferred maintenance

A factual error alone often wins an appeal without any further argument.

Comparable sales. What did similar homes in your neighborhood actually sell for in the 12 months before the assessment date? (The date matters — it’s usually January 1 of the tax year, and it’s on the notice.) Pull 3–5 sales of homes with similar size, age, and style within about a half mile. If they sold for meaningfully less than your assessed market value, you have a case.

Comparable assessments. Look up the assessed values of nearly identical neighboring homes. If your 1,800-square-foot colonial is assessed at $460,000 and the three around it are at $410,000–$425,000, that’s an “equity” argument, and many boards take it seriously.

When you probably don’t have a case: if the record is accurate and recent comparable sales support the assessed value, an appeal is unlikely to succeed. Save the afternoon.

Step 2: Build the evidence (2–3 hours)

The board wants to see a clear, factual argument. Assemble:

A copy of your assessment notice and property record card, with each error circled
3–5 comparable sales with address, sale date, price, square footage, and price per square foot, in a simple table
For each comp, a brief note on how it compares (bigger lot, newer kitchen, etc.)
Photos of any condition problems: roof, foundation, water damage, outdated systems
Repair estimates for major deficiencies, if you have them
Evidence of negative factors the model can't see: highway noise, drainage, a commercial neighbor, an easement
A recent appraisal, if you refinanced or purchased in the last year
Your closing statement if you bought recently for less than the assessed value
A one-page summary stating the value you believe is correct and why

Comparable sales are available from your county’s recorder, Zillow’s “sold” filter, Redfin, or a friendly real estate agent who can pull MLS data in five minutes. Agents often help for free because appeals are a good way to earn future business.

Step 3: Try the informal review first

Most assessors offer an informal review before the formal appeal. You call or email the office, explain the errors, and share your comps. Factual corrections are often fixed on the spot, and an appraiser may agree to adjust the value without a hearing. This costs nothing and doesn’t use up your formal appeal — but confirm the formal deadline isn’t passing while you wait.

Step 4: File the formal appeal

If the informal review doesn’t resolve it, file with the board of review (also called the board of equalization or assessment appeals board). The form is on the county site; some counties charge a small fee ($0–$50). Attach your evidence packet. Request a hearing if one isn’t automatic.

Step 5: The hearing

Hearings are short — often 10–15 minutes — and informal. A few practical rules:

Lead with the strongest point. If the record card is wrong, say that first.
Ask for a specific number, and make it supportable. Boards split differences; ask for the value the evidence supports, not a lowball.
Stay factual and calm. Complaining that taxes are too high is not an argument; the board doesn’t set rates.
Bring three copies of everything.
Address the county’s comps if they present them. Point out differences (bigger, renovated, different neighborhood).

You’ll typically get a written decision within a few weeks. If you lose, most states allow a further appeal to a state board or court; whether that’s worth it depends on the dollars.

Don’t forget exemptions

While you’re on the assessor’s site, check that you’re receiving every exemption you qualify for. The homestead exemption alone can be worth hundreds a year and is often not applied automatically. Common ones:

Homestead (primary residence)
Senior citizen (age 62–65+, often income-limited)
Disabled person or disabled veteran
Veteran or surviving spouse
Agricultural or conservation use for larger lots

An exemption you missed can sometimes be claimed retroactively for a year or two.

An afternoon of work, a few hundred dollars a year, and the satisfaction of correcting the record. Few homeowner projects have a better hourly rate.