Wisconsin Employer's Withholding Tax Guide Revised

​​​The Wisconsin Employer's Withholding Tax Guide (Publication W-166) has been updated. The withholding tables and alternate methods of withholding (A and B) have been revised due to the new top individual income tax rate of 7.75% and bracket adjustment resulting from inflation.

  • The top individual income tax rate is increased from 6.75% to 7.75% (effective for taxable years beginning on or after January 1, 2009). Interest on underpayment of estimated tax will not be charged when the estimated tax was underpaid due to the change in brackets. This applies only to the taxable year to which the bracket changes apply.
  • See page 1 of the employer's guide for other important changes.

The revised withholding tables or alternate methods should be implemented no later than October 1, 2009.

July 27, 2009