Assessment Ratio
100%
Objection Deadline
Within 45 days of Board of Review notice (2026)
Official Form
Board of Review objection form
Risk of Increase
Yes
How Assessment Works in Wisconsin
Wisconsin assesses property at 100% of fair market value. The state requires assessments to be within 10% of full value. The Department of Revenue publishes assessment ratio reports for each municipality to help ensure compliance.
Risk of Increase
In Wisconsin, filing a objection can result in your assessed value being increased. This is uncommon when you have strong evidence of over-assessment, but you should be aware of this possibility. ProtestMax only recommends filing when our analysis shows a clear case for reduction.
How to File in Wisconsin
File a written objection with the Board of Review at least 48 hours before the Board's first session. You must also appear before the Board during its session.
Step-by-Step
Wisconsin Objection Process
Receive your assessment notice from the municipal assessor.
Contact the assessor for an informal "Open Book" session (held before the Board of Review).
File a written objection with the Board of Review at least 48 hours before the first meeting.
Appear before the Board of Review and present comparable sales evidence.
If denied, appeal to circuit court within 90 days.
FAQ
Wisconsin Property Tax Objection Questions
Can my Wisconsin assessment increase on objection?
Yes. The Board of Review can increase your assessment. In fact, Wisconsin law requires you to sign a waiver acknowledging this possibility before proceeding with your objection.
What is the Open Book session?
The Open Book is an informal period before the Board of Review where you can meet with the assessor to discuss your assessment. Many issues can be resolved at this stage without a formal objection.
Do I have to appear in person in Wisconsin?
Yes. Wisconsin law requires personal appearance before the Board of Review unless you provide a sworn affidavit and submit evidence in writing by a specific deadline.