Employers in Wisconsin must conform with these state rules relating to income tax withholding and administration.
General Withholding Requirement: Wisconsin income tax must be withheld from wages paid to resident employees for services performed either within or without the state and from wages paid to nonresident employees for services performed in the state.
Employee Withholding Exemption Forms: Wisconsin Form WT-4 must be completed by each employee, to determine the appropriate level of state income tax to withhold from earnings, or the federal form can be substituted for state purposes in certain circumstances. Of course, Federal Form W-4 also must be completed by each employee, to determine the appropriate level of federal income tax to withhold from earnings.
Reciprocal Agreements: Wisconsin has reciprocal agreements in effect with Illinois, Indiana, Kentucky, and Michigan.
Administration:
Wisconsin Department of Revenue
P.O. Box 8902
Madison, Wisconsin 53708
Telephone: 608-261-6261