Miss. Code Ann. § 27-8-21

For purposes of Section 27-7-77, each resident shareholder shall be considered to have paid a tax imposed on the shareholder in an amount equal to the shareholder’s pro rata share of any net income tax paid by the S corporation to a state which does not measure the income of shareholders of an S corporation by reference to the income of the S corporation. For purposes of the preceding sentence, the term “net income tax” means any tax imposed on or measured by a corporation’s net income.