Waukesha Property Tax: Rates, Deadlines & Appeals (2026)

Direct answer: Waukesha County does not run one countywide assessment appeal deadline; Wisconsin appeals are filed with the municipal clerk for the city, village, or town where the home sits. For 2026, most Waukesha County Boards of Review have already met, but the next officially posted residential deadline I found is Menomonee Falls: oral or written notice to the Village Clerk by 3:30 p.m. on October 10, 2026—48 hours before its October 12 Board of Review. File there through Clerk Services, W156N8480 Pilgrim Rd., Menomonee Falls, WI 53051, or call 262-532-4201; otherwise use the Wisconsin DOR BOR calendar to confirm your municipality’s date.

How assessments work in Waukesha County

Your assessment is local, not countywide. Waukesha County Tax Listing maintains parcel descriptions, coordinates tax listing files, prepares tax bills for many—but not all—municipalities, and runs the county tax data warehouse. But the value you appeal is set by your municipal assessor and reviewed by your municipal Board of Review.

For 2026, the key valuation date is January 1, 2026. That is the market-value date the assessor is trying to estimate for ordinary residential property. The Village of Menomonee Falls describes 2026 as a maintenance year, meaning values generally stay the same unless something changed—new construction, an addition, demolition, remodeling/significant interior improvements, land-use/classification changes, factual corrections, or significant sales activity. Other Waukesha municipalities may be on different revaluation cycles, so do not assume your neighbor in Brookfield, Delafield, Muskego, or Waukesha city has the same assessment calendar.

The appeal calendar normally has two stages. First is Open Book, an informal chance to review the assessment roll and property record with the assessor. Menomonee Falls’ 2026 Open Book is September 29, 2026, 9:00 a.m.–noon at Village Hall. City of Delafield’s 2026 Open Book was June 29, with Accurate Assessor available 1:00–3:00 p.m. Second is the Board of Review, a formal, sworn proceeding. The Wisconsin DOR says Open Book and BOR sessions generally occur late May to mid-June, but some occur later; Menomonee Falls is the late 2026 example.

Tax bills are a separate issue. Waukesha County’s 2025 tax-rate chart—taxes payable in 2026—shows different combined rates by municipality and school district. For example, City of Waukesha / Waukesha School District shows a net rate of $13.07 per $1,000 of full/equalized value after state credit, while Village of Menomonee Falls shows net rates of $10.20 or $10.16 per $1,000 of full/equalized value depending on school district. Lake, fire district, special charges, and special assessments are not included in the chart.

Whether you should appeal

Appeal only if you can show the assessment is wrong as of January 1, 2026. A higher tax bill by itself is not enough. Good evidence includes recent comparable sales near January 1, a recent appraisal, photos and contractor estimates showing condition problems, or proof of factual errors such as finished area, basement finish, grade, lot size, or number of baths.

A quick test: convert your assessment to the county chart’s “100% equalized” context if your municipality publishes an assessment ratio. Then compare similar nearby sales. If your $525,000 assessment is in a neighborhood where similar homes sold for $475,000–$495,000 around the valuation date, an appeal may be worth it. If all comparable sales support $520,000–$540,000, your case is weak even if your taxes rose.

Worked savings example using the actual county chart: assume a City of Waukesha homeowner in the Waukesha School District gets a residential assessment reduced by $25,000. Using the 2025 chart’s $13.07 per $1,000 net full-value rate, estimated annual tax savings are 25 × $13.07 = $326.75. If the reduction is $50,000, the estimate is $653.50. Your actual savings can differ because local rates, school district, credits, special charges, and assessment ratios vary by municipality.

Do not overlook credits. The Lottery and Gaming Credit is for a Wisconsin resident who owned and used the dwelling as a primary residence on January 1; Form LC-100 is the 2026 application. The First Dollar Credit applies to every taxable parcel with a real-property improvement, not just owner-occupied homes. Lower-income homeowners should also check Wisconsin’s Homestead Credit, which is claimed through the state income-tax process and may provide an income-tax credit or direct refund.

Step-by-step how to file

1. Find your municipality and BOR date. Use the DOR Open Book / Board of Review calendar or your city/village/town assessor page. Waukesha County has many municipalities and no single appeal date.

2. Go to Open Book first if possible. Ask for your property record card and comparable sales used. Correct obvious facts before the roll is signed. Menomonee Falls says the assessor can update the assessment after Open Book if your evidence warrants it.

3. Give notice of intent on time. For all Waukesha County municipalities other than Milwaukee—which is irrelevant here—the Wisconsin rule is oral or written notice to the BOR clerk at least 48 hours before the first scheduled BOR meeting. For Menomonee Falls 2026, that means by 3:30 p.m. October 10, 2026, because the Board of Review starts October 12 at 3:30 p.m. Call Clerk Services at 262-532-4201 or use the Clerk Services contact form. City of Delafield likewise warned owners to file notice or objection 48 hours prior to its July 15, 2026 BOR.

4. File the right form. Use Wisconsin DOR Form PA-115A, Objection Form for Real Property Assessment. If an agent is appearing, add PA-105 Agent Authorization. If you want to skip the BOR hearing and ask to go directly to circuit court, file PA-813 Request for Waiver of Board of Review Hearing. If you need telephone testimony or a sworn written statement, file PA-814.

5. File with the municipal clerk, not the County Treasurer. Menomonee Falls: Village Hall, W156N8480 Pilgrim Rd., Menomonee Falls, WI 53051; Clerk Services phone 262-532-4201. City of Delafield: City Hall, 500 Genesee St., Delafield, WI 53018. City of Waukesha Board of Review contact: Sam Walker, 262-524-3510, swalker@waukesha-wi.gov. Filing by email/fax depends on the municipality; DOR says state law does not itself decide whether email or fax counts, so get written confirmation.

6. Fee: Wisconsin’s BOR materials and the Waukesha municipal pages reviewed do not list a fee for filing a BOR assessment objection. If you later appeal in circuit court, court filing fees apply.

What happens after

The Board of Review is the proper appeal authority. Its exact name is usually [Municipality] Board of Review—for example, Village of Menomonee Falls Board of Review, City of Delafield Board of Review, or City of Waukesha Board of Review.

The hearing is quasi-judicial. You and the assessor present evidence under oath. The assessor’s value is presumed correct, and the burden is on you to prove a different value. The board may affirm, lower, or raise the assessment based on the evidence. Proceedings and deliberations must be recorded in the clerk’s minutes and by stenographer or recording device.

If you cannot appear, PA-814 lets you request sworn telephone testimony or a sworn written statement; the BOR decides whether to accept it unless you qualify under the illness/disability rule. For complex cases, PA-813 lets you request a waiver of the BOR hearing so you can proceed to circuit court, but the board may deny the waiver.

The decision is not just verbal. The BOR must send a written Notice of Board of Review Determination, by personal delivery or certified mail, showing the final assessment and appeal rights. If you continue to appeal, pay attention to the notice date; DOR explains that circuit-court deadlines can be 90 days under sec. 70.47(13) or 60 days under sec. 74.37 after certain waiver decisions.

Local tips

Use Waukesha County’s tax listing search and recorded-document search to verify parcel number, legal description, lot size, sale documents, and your tax bill. County tax parcel numbers begin with municipal letters followed by numbers, which helps you confirm you are comparing the correct municipality.

Do not mail BOR forms to the County Treasurer unless your municipal clerk specifically tells you to. The Treasurer is essential for bills and payments—many municipalities have January 31 and July 31 due dates, with some three-installment cities such as Waukesha, New Berlin, Sussex, and Oconomowoc—but that office does not decide your assessment appeal.

For evidence, stay hyper-local. A Menomonee Falls ranch should be compared with similar Menomonee Falls ranches, not lake homes in Chenequa or newer subdivisions in Delafield. Adjust for school district, municipal services, lake districts, lot size, finished basement, garage, and condition. If you are appealing because of a defect, bring dated photos, inspection reports, bids, and a concise value conclusion—not just a complaint.

Finally, check the credit boxes on your December bill. Waukesha County’s rate chart shows maximum Lottery and First Dollar credits by school district, and missing credits can cost real money even when your assessment is correct.

Waukesha County Property Tax Rate

No single countywide homeowner millage applies to every parcel. For 2025 tax bills payable in 2026, Waukesha County's official rate chart lists total gross tax rates of $7.61–$17.82 per $1,000 of assessed value and net assessed rates after the state credit of $6.42–$16.67 per $1,000; the county-tax component shown on that chart ranges from $1.28–$2.23 per $1,000 assessed value. Rates are rounded and exclude lake districts, fire districts, special charges, and assessments.

Source: https://www.waukeshacounty.gov/media/2skgz23v/tax-rates-2025.pdf

When Are Property Taxes Due in Waukesha County?

Property-tax payment due dates vary by municipality: most Waukesha County municipalities list January 31 and July 31; Muskego City and Oconomowoc City list January 31, April 30, and July 31; New Berlin City, Sussex Village, and Waukesha City list January 31, March 31, and May 31. If the tax bill qualifies for installments and the taxpayer chooses installments, each installment must be paid by its due date or the remaining unpaid taxes, special assessments, and special charges become delinquent.

This is not the same as the assessment appeal deadline above. The appeal deadline is your window to contest your assessed value; the payment due date is when the resulting tax bill must be paid. Missing one does not affect the other, but missing either has real consequences — one forfeits your right to appeal for the year, the other can trigger penalties and interest.

Source: https://www.waukeshacounty.gov/media/atopfvjq/tax-due-date-chart.pdf

Property Tax Exemptions in Waukesha County

• Wisconsin Lottery and Gaming Credit — Wisconsin residents who own a dwelling and use it as their primary residence as of the January 1 certification date; only one primary residence generally qualifies.. Varies by school tax rate and the DOR maximum credit value; for 2025-2026, DOR set the Lottery and Gaming maximum credit value at $27,000, and the credit is shown as a reduction on the property tax bill. Yes; file with the county treasurer, or city treasurer if the property is in a city that collects taxes under state law, if the credit is not already on the bill. Apply by January 31 after the tax bill is received; late claim with Wisconsin DOR by October 1 after the bill is issued.. (Source: https://www.revenue.wi.gov/Pages/FAQS/slf-lottcr.aspx)
• Wisconsin First Dollar Credit — Every taxable parcel containing a real property improvement, including private residential property with a qualifying real-property improvement; it does not have to be the owner's primary residence.. Varies by applicable school tax rate and maximum credit value; for 2025-2026, DOR set the First Dollar maximum credit value at $9,000, and the amount appears on the property tax bill's First Dollar Credit line. No, automatically applied to qualifying properties. (Source: https://www.revenue.wi.gov/Pages/FAQS/slf-fdolcred.aspx)
• Wisconsin School Levy Tax Credit — All taxable real property in Wisconsin qualifies.. Varies; the amount is listed on the property tax bill below the Net Assessed Value Rate box. No, applied directly to the property tax bill for taxable real property. (Source: https://www.revenue.wi.gov/Pages/faqs/slf-ptrecred.aspx)
• Wisconsin Homestead Credit — For the 2025 claim year, Wisconsin legal residents for all of 2025 who are age 18 or older on December 31, 2025, have household income under $24,680, own or rent a Wisconsin homestead subject to property taxes, and meet the DOR's other conditions, including earned income, disability, or age 62+ status.. Varies; calculated on Schedule H or H-EZ based on household income and allowable property taxes or rent. Yes, file Wisconsin Schedule H or Schedule H-EZ and attach the required property tax bill or rent certificate. Apply by For most 2025 claimants: 2030-04-15.. (Source: https://www.revenue.wi.gov/Pages/FAQS/ise-home.aspx)
• Wisconsin Veterans and Surviving Spouses Property Tax Credit — Eligible veterans certified by the Wisconsin Department of Veterans Affairs, generally including Wisconsin-resident veterans with a 100% service-connected disability rating or 100% rating based on individual unemployability, and eligible unremarried surviving spouses certified by WDVA.. Credit equals the property taxes paid during the year on the eligible veteran's or surviving spouse's principal dwelling and up to one acre of surrounding land reasonably necessary for the residence; no dollar limit is stated by DOR for qualifying property taxes. Yes, obtain WDVA eligibility verification, claim on the Wisconsin income tax return, and attach required verification, property tax bills, and proof of payment as required. Apply by Must be claimed within four years of the unextended due date of the Wisconsin income tax return.. (Source: https://www.revenue.wi.gov/Pages/FAQS/ise-vetqual.aspx)
• Wisconsin Farmland Preservation Credit — Eligible Wisconsin resident farm owners with qualifying farmland under a farmland preservation agreement, zoning district, or area, meeting DOR requirements including gross farm profits, paid or legally owed property taxes, and soil and water conservation compliance.. Varies by schedule and eligibility; Schedule FC-A is a flat $10 or $12.50 per qualifying acre, with DOR listing a $4,200 maximum for one category and no limitation for another category. Yes, file Schedule FC, Schedule FC-A, or both as applicable, with required documentation such as tax bills and compliance information. Apply by Generally no later than four years after the unextended due date of that year's income tax return.. (Source: https://www.revenue.wi.gov/Pages/FAQS/ise-farm.aspx)

How to Look Up Your Property Record in Waukesha County

You can look up your property's official record at https://tax.waukeshacounty.gov/. Waukesha County's official Property Tax Listing search lets users search by tax key or address and provides pay options, tax bill details, and property details from county and local-government data.