Walworth County Property Assessment Appeal | How to Win in 5 Steps (Open Book to Board of Review)

Updated October 22, 2026. Deadlines and figures reflect the latest published sources as of this date.

Your assessment notice says your home is worth more than you could sell it for. Or your December tax bill jumped and you are not sure why. Either way, Wisconsin gives you one short window each year to fix it, and most owners miss it because they don't know the window exists.

This guide walks through a Walworth County property assessment appeal from start to finish: how to check whether your assessment is actually too high, what to bring to Open Book, how to file with the Wisconsin Board of Review, and what happens if you lose. You will also see why Geneva Lake owners above $1 million have fewer options and need to get the first hearing right.

Who Sets Your Assessment in Walworth County?

Not the county. Wisconsin has no county assessors, according to the Wisconsin Department of Revenue's 2026 Guide for Property Owners. Each city, village, and town hires its own assessor and runs its own Board of Review. The City of Lake Geneva, for example, contracts with Associated Appraisal Consultants for all assessment work.

That means your dates, your clerk, and your assessor depend on your municipality, not on Walworth County.

Why Assessments Are Climbing

Wisconsin's total equalized property value hit $1.057 trillion as of January 1, 2026, up 8% in a year, per the Department of Revenue's 2026 equalized values report. Residential value alone rose 7%. When markets move that fast, individual assessments can drift away from what a specific home would really sell for.

Remember the key rule of any Wisconsin Board of Review property tax dispute: the board hears disputes about value, not about taxes. "My taxes are too high" is not a case. "My home is assessed above market value" is.

Walworth County Appeal Timeline at a Glance

January 1: Your assessment is set as of this date, based on market value, per the DOR guide.

Spring: If your value changed, your assessor must mail a Notice of Changed Assessment at least 15 days before the Board of Review (30 days in a revaluation year).

Open Book: An informal review with the assessor, held at least 7 days before the Board of Review.

48 hours before the Board of Review: Your notice of intent to object is due to the clerk.

Board of Review: Meets during a 45-day window starting the fourth Monday in April, though many towns adjourn to a later date.

Dates vary widely across the county. The Town of Walworth typically holds Open Book in May and its Board of Review in June, while the Town of Geneva has run both into late June and July. Check your municipality's website or call the clerk each spring for that year's dates.

How to File a Walworth County Property Assessment Appeal in 5 Steps

Step 1: Check Whether Your Assessment Is Actually Too High

Do not compare your assessment to your neighbor's. The DOR guide says outright that this is a mistake, and boards will not change a value on that basis. Instead, compare your assessment to market value.

Divide your assessed value by your home's current market value. That gives your assessment ratio. Then ask the assessor for your municipality's assessment level. If your ratio is close to that level, your assessment is equitable. If yours is well above it, you may have a case.

Also pull your property record card. Wrong square footage, a phantom bathroom, or a finished basement that isn't finished are the easiest wins.

Step 2: Gather Evidence the Board Will Accept

Wisconsin ranks evidence in a clear order, per the DOR guide. The strongest is a recent arm's-length sale of your own home, so if you bought it recently on the open market, that price carries the most weight. Next come recent arm's-length sales of similar homes, matched as closely as you can on location, style, age, size, and features. When good sales don't exist, a recent appraisal, cost data, or income data can fill the gap.

Bring closed sales, not asking prices. For help reading lakefront comps, see how Lake Geneva home values are actually calculated.

Step 3: Use Your Wisconsin Open Book Assessment Review

Open Book is informal, and it is where most problems should end. The assessor can correct the roll on the spot. Once Open Book closes, any change requires the formal Board of Review process or circuit court.

Book early. In the City of Lake Geneva, appointments go through Associated Appraisal at (920) 749-1995, not City Hall. Bring your record card, your sales, and a specific number you think is fair.

Step 4: File Your Objection With the Board of Review

If Open Book does not fix it, you need two things, per the DOR guide and Wis. Stat. § 70.47:

• A notice of intent to object, written or oral, given to the Board of Review clerk at least 48 hours before the board's first meeting. No special form is required, but put it in writing.
• The completed Objection to Real Property Assessment form (PA-115A), filed before or during the first two hours of the board's first meeting.

The board can waive the 48-hour notice for good cause, but do not count on it. You must object to the total value, not just the land or just the house.

Step 5: Present Sworn Testimony at the Hearing

The Board of Review works like a court. Your assessor's value is presumed correct, so the burden is on you. You must give the board, in writing, your estimate of the land and improvement values and explain how you reached them.

Keep it tight: your number, your three best sales, adjustments for differences, and any record errors. The assessor then presents their side, and you can ask questions. If you cannot attend, ask the clerk whether the board accepts phone testimony or a sworn written statement.

What If You Lose at the Board of Review?

You have three paths, each with a hard deadline, per the DOR guide:

Appeal to the Department of Revenue. The department must receive your written complaint within 20 days after you receive the board's decision (or within 30 days of the mailing date on the clerk's affidavit if there was no return receipt), with a $100 fee. This option is not available if the assessed value is over $1 million.

Appeal to circuit court. File within 90 days after you receive the board's decision. The judge reviews only the Board of Review record. No new evidence is allowed.

Excessive assessment claim. File with your municipality by January 31 of the year the tax is payable, and pay your taxes on time. You generally must have gone to the Board of Review first, and this path is closed if you already appealed to the department or circuit court. Pick one route.

This is where many Geneva Lake owners get caught. Above $1 million, the state appeal is off the table, and a circuit court judge only sees what you put on the record at the hearing. A thin first presentation is hard to fix later.

Illustrative Scenario: A Town of Geneva Owner

Consider a homeowner in the Town of Geneva whose notice shows $650,000. Three recent arm's-length sales of similar homes nearby point to about $590,000. Assume the town is assessing close to full value.

Using the Town of Geneva's 2024 net rate of about $10.54 per $1,000 (before any sanitary district or special charges), built from the components the Walworth County Treasurer publishes and broken out in our Lake Geneva property taxes guide, a $60,000 reduction cuts the bill by about $632 a year.

Now the fork. Say the assessor reviews those sales at Open Book and agrees to $610,000. That saves about $422 a year with no hearing. Or the owner holds out for $590,000 and files with the Board of Review, where the assessor's number is presumed correct and the board decides on sworn evidence. Taking a fair Open Book offer is often the smarter play unless the sales are strong and recent.

Two cautions. Each year's assessment is a new assessment, so the savings are not locked in. And rates change every year. Still, a few hours with the right sales can be worth it.

Pros and Cons of Appealing Your Assessment

Pros

• Open Book is free and informal, and fixes many errors without a hearing
• A successful appeal lowers that year's bill and documents your evidence for future years
• You can represent yourself, with no attorney required at the local level

Cons

• The assessor is presumed correct, so weak evidence loses
• The board can raise a value as well as lower it if the evidence supports it
• Deadlines are short, and missing the 48-hour notice can end your appeal
• Later appeals are limited, especially above $1 million

Missed the Board of Review? What You Can Still Do

Once your municipality's Board of Review adjourns, that year's assessment is final, and you can't start a new objection until the next cycle. Your options depend on where you are in the process.

If you appeared before the Board of Review and still disagree, you can file an excessive assessment claim with your municipality by January 31 of the year the tax is payable, as long as you pay your taxes on time and haven't appealed to the department or circuit court. If you never filed, use the time to prepare for next year: compare your tax bill to what you know the home is worth, keep track of comparable sales as they close, and watch for your assessment notice and your municipality's Open Book date each spring. And if you are budgeting for a lake home, factor assessment risk into the full picture in what it really costs to own a lake house.

The Bottom Line

A Walworth County property assessment appeal comes down to evidence and timing. Check your ratio, bring real sales to Open Book, and file both the 48-hour notice and the PA-115A form if you need the Board of Review. Get the first hearing right, because later options are narrow.

Need closed sales to back up your number? Legendary Real Estate Services can pull comparable sales for your property before your next Open Book. Contact our team or call (262) 204-5534.

Frequently Asked Questions

How do I appeal my property assessment in Walworth County?

Start with your municipality's assessor at Open Book. If that does not resolve it, give the Board of Review clerk a notice of intent at least 48 hours before the board's first meeting, file the PA-115A objection form, and present sworn evidence at the hearing. Each city, village, and town in Walworth County sets its own dates.

What is Open Book in Wisconsin?

Open Book is the period before the Board of Review when the assessment roll is open and you can meet the assessor informally. It must happen at least 7 days before the Board of Review. The assessor can correct your value at Open Book. After it closes, changes require the formal Board of Review or circuit court.

What evidence does the Wisconsin Board of Review accept?

The strongest evidence is a recent arm's-length sale of your own home. Next is recent arm's-length sales of comparable homes. Without those, an appraisal, cost, or income data can help. Comparing your assessment to a neighbor's assessment is not accepted, and the board will not hear complaints that taxes are too high.

What is the deadline to file with the Board of Review?

You must give the Board of Review clerk written or oral notice of your intent to object at least 48 hours before the board's first scheduled meeting. The completed PA-115A objection form is due before or within the first two hours of that meeting. The board can waive the notice for good cause.

Can I appeal if my home is worth more than $1 million?

Yes, at the Board of Review. After that, the Department of Revenue appeal is not available when the assessed value is over $1 million. Your remaining options are a circuit court appeal within 90 days after you receive the board's decision, which reviews only the hearing record, or an excessive assessment claim filed with your municipality by January 31.

Can my assessment go up if I appeal?

It can. The Board of Review decides the correct value based on the sworn evidence presented, and the assessor's value is presumed correct. If the evidence supports a higher number, the board can raise it. Bring closed sales of truly similar homes so the evidence points where you expect.