If you want your state income tax cut right away, you need to file paperwork with your employer.
The 2013-15 budget state leaders approved in June to take effect this month, contains a $650 million cut in state income taxes. However, the state is not adjusting its withholding tables - so paychecks won't automatically be bigger.
If you want to experience the tax cut right away, you need to fill out paperwork with your employer, so it withholds less in state taxes each paycheck. Otherwise, you won't see the lower rate until you file your state income tax next year.
Historically, Wisconsin has not lowered its withholding tables during the year, so the state can collect more tax revenue for the time being, according to Todd Berry, president of the Wisconsin Taxpayers Alliance.