Income tax.

For the purpose of raising revenue for the state and the counties, cities, villages and towns, there shall be assessed, levied, collected and paid a tax as provided under this chapter on all Wisconsin net incomes of corporations that are not subject to the franchise tax under sub. (2) and that own property within this state; that derive income from sources within this state or from activities that are attributable to this state; or whose business within this state during the taxable year, except as provided under sub. (3), consists exclusively of foreign commerce, interstate commerce, or both, or that buy or sell lottery prizes if the winning tickets were originally bought in this state; except as exempted under s. 71.26 (1). This section shall not be construed to prevent or affect the correction of errors or omissions in the assessments of income for former years under s. 71.74 (1) and (2).