The property tax process begins with assessments, which are conducted by the local municipality (city, town, village). Property assessments represent the values of the property as of January 1 of a given year. A reevaluation could be annually or every few years.
When assessments are determined for the year (typically March or later), property owners are sent a Notice of Assessment from the local assessor. Property owners are provided a period of time to discuss the assessment with the assessor during Open Book and appeal to the municipality's Board of Review. After the period for appeal has passed, it would normally be too late for the property owner to appeal the assessed property value for the given year.
Wisconsin taxing districts (municipalities, schools, counties, etc.) set their budgets in the fall, usually November. Then, property tax is calculated in December based on the individual property assessments and the levies of the overlying taxing jurisdictions. Once calculated, bills are printed for mailing by the 3rd Monday in December.
Payment information (amount, due dates, who to pay, etc.) can be found on the tax bill sent in December. At least the first installment amount is due January 31 to the local municipality. The final installment is paid by July 31 to Dane County, EXCEPT for properties in the City of Madison.*
In determining whether a payment is timely, the treasurer's office goes by the postmark affixed by the US Postal Service. If at least the installment amount is not paid by the due date listed on the tax bill and the taxes become delinquent, the following occurs:
*The City of Madison has intermediate installments, and payments for properties within the City of Madison are collected by the City Treasurer through the July 31 due date. Information regarding City of Madison due dates and amounts for the current tax year can be obtained by contacting the City of Madison Treasurer: