Income and franchise taxes paid to another state by a tax-option corporation, partnership, or limited liability company that is treated as a partnership may be claimed as a credit under this paragraph by that corporation’s shareholders, that partnership’s partners, or that limited liability company’s members who are residents of this state and who otherwise qualify under this paragraph, unless the tax-option corporation, partnership, or limited liability company has made an election under s. 71.21 (6) (a) or 71.365 (4m) (a).

Subject to the conditions and limitations in pars. (c) and (d), if a tax-option corporation, partnership, or limited liability company makes an election under s. 71.21 (6) (a) or 71.365 (4m) (a), that tax-option corporation, partnership, or limited liability company may credit the net income or franchise tax paid by the entity to another state on that income and the net income tax on that income paid by the entity on behalf of its shareholders, partners, and members that are residents of this state on a composite return filed with the other state against the net income or franchise tax otherwise payable to this state on income of the same year. The credit may not be allowed unless the income taxed by the other state is also considered income for Wisconsin tax purposes and is otherwise attributable to amounts that would be reportable to this state by shareholders, partners, or members of the tax-option corporation, partnership, or limited liability company that are residents of this state if the election under s. 71.21 (6) (a) or 71.365 (4m) (a) was not made. The credit may not be allowed unless claimed within the time provided in s. 71.75 (2), but s. 71.75 (4) does not apply to those credits. For purposes of this subdivision, amounts declared and paid under the income tax law of another state are considered a net income tax paid to that other state only in the year in which the income tax return for that state was required to be filed.