January 1:
Assessment Date - All property is assessed as it existed on this date

January 31:
Full payment of taxes due OR if paying in installments, due date of first tax installment payment (Installment payment option is not available for personal property taxes)

Second Monday in May:
Board of Review meets anytime after the 2nd Monday in May. Each municipality sets an open book & Board of Review dates. Please contact your assessor for the exact date.

July 31:
Second tax installment payment due date

Property taxes as levied are collected by local treasurers typically through the last day of January in each year. At this time, a settlement process between the County Treasurer and local treasurers determines the amount due to the various taxing districts. Real property taxes are payable by taxpayers in full by the last day of January or in two installments due by January 31st and July 31st. Personal property taxes are due in full by the last day in January.

Local municipalities can adopt an ordinance for multiple payments. City of Wausau has an ordinance for January 31st, April 30th, and July 31st payments.

Many local treasurers have part-time offices. They mail schedules for office house with tax bills and prefer payments by mail.