Wisconsin Property Tax Appeal Guide
Wisconsin municipalities assess property at full (market) value, with an assessment ratio published where local values deviate from the market.
100%
Statutory percentage
Last day of open book (Board of Review)
Verified July 2026 — confirm on your notice
Wis. Stat. § 70.47 (board of review)
Governing state code
How to File in Wisconsin
Review your assessment during the municipality's Open Book period.
Discuss the value with the assessor during Open Book.
File a written or oral objection and appeal to the local Board of Review.
Present comparable sales supporting a lower value under oath at the hearing.
Appeal to circuit court by certiorari or the Department of Revenue if needed.
Deadlines and ratios vary by county and change over time — always confirm with your local assessor. This is general information, not legal advice.
Are you actually over-assessed in Wisconsin?
Check this property against recent comparable sales for $4.99. If the evidence says you have no case, you know that before you spend a filing deadline on it — and if it does, the same $4.99 is credited toward the full appeal packet.
A worked example in Wisconsin
Say the assessor values your home at $400,000, but comparable sales show it is really worth $350,000 — a $50,000 over-assessment. Wisconsin taxes the full market value, so the taxable amount drops by the same amount. At a typical effective rate of ~1.5%, that is about $750 back in your pocket every year until the value is corrected.
Illustration only. Your actual rate, exemptions, and savings depend on your county and taxing districts — run your own numbers.
Common grounds for a Wisconsin appeal
Over-market valuation. Comparable sales of similar nearby homes closed below the value the assessor placed on yours.
Errors in the property record. The county has the wrong square footage, bedroom or bathroom count, lot size, or condition on file.
Unequal (non-uniform) assessment. Comparable properties in your area are assessed for less than yours, regardless of market value.
Physical or external problems. Deferred maintenance, functional issues, or an external nuisance depress what a buyer would pay.
Overvaluation · Unequal assessment · Denial of exemption
Don’t overlook exemptions
An appeal lowers your value, but exemptions cut your taxable base directly — and both stack. Most owners qualify for a homestead exemption on their primary residence, and many states add relief for owners over 65, veterans, and people with disabilities. Confirm you are enrolled with your Wisconsin county assessor before filing — it is the fastest saving most people miss.
- Lottery and Gaming Credit Varies (based on school levy)
- Owner-occupied primary residence
- First Dollar Credit Varies
- All taxable real property
- Veteran/Surviving Spouse Full exemption
- 100% disabled veteran
Who hears a Wisconsin appeal
Your appeal is decided by Board of Review — the value itself is set by the Municipal Assessor, which is who you are disagreeing with.
- 1
Board of Review
- 2
Wisconsin Tax Appeals Commission
- 3
Circuit Court
Each stage has its own deadline. Missing the first one usually closes the later ones for that tax year.
Key Wisconsin statutes
The sections a Wisconsin appeal is argued under. Quote one exactly as written — a paraphrased or renumbered citation is worse than none.
- Wis. Stat. §70.32
- Assessment of Real Property
- Wis. Stat. §70.47
- Board of Review
- Wis. Stat. §73.01
- Tax Appeals Commission
- Wis. Stat. §70.11
- Exemptions
Official Wisconsin resources
These are state government sites. The form and portal you actually file through are published by your county assessor.
Wisconsin property tax appeal questions
- When is the deadline to appeal property taxes in Wisconsin?
- Last day of open book (Board of Review). Verified July 2026. Deadlines vary by county and change from year to year, so always confirm the date printed on your own assessment notice before you file.
- Who decides a property tax appeal in Wisconsin?
- Board of Review hears it. The full path is: Board of Review, then Wisconsin Tax Appeals Commission, then Circuit Court.
- What is the assessment ratio in Wisconsin?
- 100% of fair market value. That is the share of value your bill is calculated on, so lowering the assessed value lowers the bill proportionally.
- What grounds can I appeal on in Wisconsin?
- Wisconsin recognises these grounds: Overvaluation, Unequal assessment, Denial of exemption. Overvaluation is the most common — you show comparable sales that closed below your assessed value.
- What property tax exemptions does Wisconsin offer?
- Lottery and Gaming Credit — Varies (based on school levy), for owner-occupied primary residence; First Dollar Credit — Varies, for all taxable real property; Veteran/Surviving Spouse — Full exemption, for 100% disabled veteran. Exemptions reduce your taxable base directly and stack with an appeal, so check both.
- What is the average property tax rate in Wisconsin?
- About 1.32% of market value per year statewide. Your own rate depends on your county and its taxing districts, so treat this as a benchmark rather than your bill.
Wisconsin Tax Estimator
$0 / yr
Based on 100% ratio & avg. millage. Estimate only.
Generate your Wisconsin appeal packet
Check your property for $4.99 (credited), then get the full comparable-sales packet and AI appeal letter for a flat $29 — $19 at launch.