Multiply the taxpayer’s highest applicable tax rate under s. 71.06, 71.27, or 71.46, by the amount of any increase in Wisconsin taxable income that results from the difference between the proper tax treatment of a reportable transaction and the taxpayer’s treatment of the transaction as shown on the taxpayer’s tax return, including any amended return the taxpayer files before the date on which the department first contacts the taxpayer regarding an examination of the taxable year for which the amended return is filed. For purposes of this subdivision, the amount of any increase in Wisconsin taxable income for a taxable year includes any reduction in the amount of loss available for carry-forward to the subsequent year.

Add the amount determined under subd. 1. to the amount of any decrease in the aggregate amount of Wisconsin income or franchise tax credits that results from the difference between the proper tax treatment of a reportable transaction and the taxpayer’s treatment of the transaction as shown on the taxpayer’s tax return.