Why am I charged for sales tax for only part of the year?
In Wisconsin, the cost of electricity used for residential purposes is subject to sales tax on bills issued in May through October. During the remainder of the year, charges are exempt from sales tax since some of the electricity may be used for residential heating purposes during those months.
Charges for water and sewer utilities are exempt from sales tax all year.
The determination of what utility charges are subject to sales tax is made by the Wisconsin Department of Revenue.