You should appeal if your assessed value is higher than what similar homes in your area actually sell for

A property tax assessment is the value your local assessor assigns to your home for tax purposes. That value determines how much you pay in property taxes each year. If the assessment is wrong — if it overstates what your home is worth — you are paying more tax than you should. An appeal challenges that assessment and asks the assessor to lower it.

The decision to appeal comes down to three things: whether you have evidence the assessment is too high, whether your county or township actually allows appeals, and whether the cost and time are worth the potential savings. Most assessments are reasonably accurate, but mistakes happen. A home might be assessed at $350,000 when comparable homes nearby sold for $280,000. That gap is worth pursuing. A home assessed at $300,000 when it sold for $305,000 last year is probably not.

You do not need a lawyer or a professional appraiser to appeal, though some people hire them. Many successful appeals are filed by the homeowner alone, using public sales records and a clear written argument about why the assessment is wrong.

Key Takeaways

  • You can appeal if your assessed value is significantly higher than what homes like yours have sold for recently in your area.
  • The appeal important date is usually 30 to 45 days after you receive your assessment notice, so check your notice when ready for the exact date.
  • Most appeals are filed with your county assessor's office or a local board of review, not with a state agency.
  • You will need comparable sales data — actual prices homes sold for — to support your case, which you can find through public records or real estate websites.
  • If your appeal is denied, many counties allow a second appeal to a county board or court, though the process and important date differ by location.

When the assessment is actually wrong

An assessment is wrong when it does not match the market value of your home. Market value means what a buyer would pay for it today, not what you paid for it years ago or what you think it should be worth.

The clearest sign is a gap between your assessed value and recent sales of similar homes. If three homes on your street sold in the last year for $275,000, $280,000, and $285,000, and your home is assessed at $340,000, that is a problem. Your assessor may have made a data entry error, used outdated information, or misclassified your property. The assessment might reflect an addition or renovation that was never actually completed, or it might be based on a sale price from a decade ago.

A smaller gap — your home assessed at $300,000 when comparable homes sold for $295,000 — is usually not worth appealing. Assessments are estimates, and small variations are normal. Most counties consider an assessment reasonable if it is within 10 percent of market value. A gap of 15 percent or more is a stronger case.

Physical errors also matter. If your home is listed as having four bedrooms when it has three, or if the square footage is off by 500 square feet, that can justify an appeal even if the overall value seems close. Contact your assessor's office first and ask them to verify the property details. Many errors are corrected without a formal appeal.

How to find comparable sales in your area

Your appeal will rest on evidence. That evidence is comparable sales — homes similar to yours that sold recently. You need to show what those homes actually sold for, not what they were listed for.

Start with your county assessor's website. Most counties publish sales data online, searchable by address or neighborhood. You can see what homes sold for, when they sold, and sometimes the square footage and lot size. This is public record and free to access.

Real estate websites like Zillow, Redfin, and Realtor.com also show recent sales prices and property details. These sites are less official than county records but are usually accurate for recent transactions. Filter by your neighborhood, your home's age and size, and sales from the last 12 to 18 months. You need at least three comparable sales to make a credible case, though five or more is stronger.

When selecting comparables, match as closely as you can: same neighborhood or adjacent neighborhoods, similar square footage (within 10 percent), similar age, similar condition, and similar lot size. A home that sold two blocks away last month is more useful than one that sold three years ago across town. Write down the address, sale price, sale date, square footage, and lot size for each comparable. This becomes your evidence.

The appeal process and important date

The appeal process varies by county and state, but the basic steps are the same. You file a written challenge with the assessor's office or a local board of review by a set important date. You present your evidence. The assessor or board reviews it and decides whether to lower the assessment.

The important date is critical. Most counties give you 30 to 45 days from the date you receive your assessment notice to file an appeal. Some allow longer if you miss the first important date but file within a second window. Check your notice when ready — it will state the exact important date for your county. If you miss it, you usually cannot appeal that year.

The first step is to contact your county assessor's office and ask where and how to file. Some counties want a formal written petition. Others accept a letter. Ask what documents they need: your comparable sales data, your property details, and an explanation of why you believe the assessment is wrong. Some offices have a form to fill out; others do not.

Write a clear, one-page letter stating your assessed value, the market value you believe is correct based on comparable sales, and why the assessment is too high. Attach your comparable sales data. Be factual and specific. Do not argue that you cannot afford the taxes or that you deserve a lower value — assessments are based on market value, not on your finances.

What happens after you file

After you submit your appeal, the assessor's office or board of review will review it. This usually takes 30 to 90 days. Some counties hold a hearing where you can present your case in person; others decide based on written submissions alone. Ask your assessor's office whether a hearing is automatic or whether you need to request one.

If you attend a hearing, bring your comparable sales printouts and be ready to explain why those homes are similar to yours and why their sale prices show your assessment is too high. Keep it brief and factual. The assessor or board member will ask questions. Answer directly.

The assessor or board will then issue a decision. If they agree with you, they will lower the assessment, and your property taxes will drop. If they disagree, the assessment stays the same. Some counties allow a second appeal to a county board of review or to tax court, but the important date for that second appeal is usually short — 30 days or less. Check your decision letter for the important date and process.

When to hire help and what it costs

Many homeowners file appeals on their own and win. You do not need a professional unless the case is complex or your county's process is difficult to navigate.

A tax assessment consultant or property tax attorney can help if your home is unusual, if the assessor's data is significantly wrong, or if you have already lost an appeal and want to file a second one. Consultants typically charge a flat fee of $300 to $800 or take a percentage of the tax savings — usually 25 to 50 percent of the first year's reduction. If your appeal saves you $1,000 per year, a consultant taking 40 percent would cost $400 in year one. That is worth it if you would not have filed alone.

A lawyer is rarely necessary unless you are appealing to tax court. Most county-level appeals do not require legal representation. If you do hire a lawyer, expect to pay $150 to $400 per hour, though some work on contingency (taking a percentage of savings instead of an hourly fee).

Before hiring anyone, ask what they charge, what they may provide (they should may provide nothing — no one can promise an appeal will succeed), and whether they have experience with appeals in your specific county. Check whether your county has a free or low-cost assessment review service run by a nonprofit or government office.

Why some assessments are hard to challenge

Not all high assessments are wrong, and not all appeals succeed. An assessment might be high because your home has features that increase its value: a recent renovation, a larger lot, or a desirable location. If those features are real and comparable homes with the same features sold for similar prices, the assessment is probably correct.

Some assessments are hard to challenge because comparable sales are scarce. In a rural area or a neighborhood where homes rarely sell, you may not have enough recent sales data to make a strong case. In that situation, you might hire an appraiser to estimate your home's value, but that costs $400 to $800 and is only worth it if the potential tax savings are large.

Assessors also use different methods. Some use recent sales data. Others use income approaches (for rental properties) or cost approaches (rebuilding cost plus land value). If your assessor used a method that does not match your market value, explaining that mismatch in your appeal can help, but it requires understanding how your county assesses property. Ask your assessor's office which method they used and whether they have written guidelines you can review.

Frequently Asked Questions

What if I just bought my home — can I appeal the assessment right away?

Yes, but the timing matters. If you bought at a price lower than the current assessment, you have a strong case. If you bought at a higher price, the assessor will likely use your purchase price as evidence the assessment is correct. Most appeals are strongest within one to two years of a significant change in market value, not when ready after purchase.

Will appealing my assessment cause the assessor to raise it instead?

No. Assessors cannot raise an assessment as punishment for filing an appeal. The assessment can only stay the same or go down. This protection exists in all states.

How long does it take to see a lower tax bill after my appeal is approved?

Usually one to two years. The assessor will lower the assessment, but the new value typically takes effect in the next tax year. Some counties explore it when ready; others wait until the next assessment cycle. Ask your assessor's office when the change will appear on your bill.

Can I appeal every year, or just once?

You can appeal every year if the assessment changes or if you believe it is still wrong. However, if you appeal and lose, appealing again the next year with the same evidence will likely fail. Appeal again only if the market has shifted significantly or if you have new evidence.

What if my county does not have a board of review — where do I appeal?

Contact your county assessor's office directly. They will tell you the process for your county. Some counties have an assessor's review board, others route appeals to a county tax assessor's office, and still others use a state-level board. The process varies, but every county has a way to challenge an assessment.