(1) Except as otherwise specifically provided, a financial institution whose business activity is taxable both within and without this state shall allocate and apportion its net income as provided in Sections 27-7-24, 27-7-24.1, 27-7-24.3, 27-7-24.5 and 27-7-24.7, Mississippi Code of 1972. All items of nonbusiness income (income which is not includable in the apportionable income tax base) shall be allocated pursuant to the provisions of Section 27-7-23, Mississippi Code of 1972. A financial institution organized under the laws of a foreign country, the Commonwealth of Puerto Rico, or a territory or possession of the United States whose effectively connected income, as defined under the federal Internal Revenue Code, as in effect January 1, 1996, is taxable both within this state and within another state, other than the state in which it is organized, shall allocate and apportion its net income as provided in Sections 27-7-24, 27-7-24.1, 27-7-24.3, 27-7-24.5 and 27-7-24.7, Mississippi Code of 1972.

(2) All business income (income which is includable in the apportionable income tax base) shall be apportioned to this state by multiplying such income by the apportionment percentage. The apportionment percentage is determined by adding the taxpayer’s receipts factor (as described in Section 27-7-24.3), property factor (as described in Section 27-7-24.5), and payroll factor (as described in Section 27-7-24.7) together and dividing the sum by three (3). If one (1) of the factors is missing, the two (2) remaining factors are added and the sum is divided by two (2). If two (2) of the factors are missing, the remaining factor is the apportionment percentage. A factor is missing if both its numerator and denominator are zero (0), but is not missing merely because its numerator is zero (0).

(3) Each factor shall be computed according to the method of accounting (cash or accrual basis) used by the taxpayer for the taxable year.

(4) If the allocation and apportionment provisions of Sections 27-7-24, 27-7-24.1, 27-7-24.3, 27-7-24.5 and 27-7-24.7 do not fairly represent the extent of the taxpayer’s business activity in this state, the taxpayer may petition for or the commissioner may require, in respect to all or any part of the taxpayer’s business activity, if reasonable:

(a) Separate accounting;

(b) The exclusion of any one or more of the factors;

(c) The inclusion of one or more additional factors which will fairly represent the taxpayer’s business activity in this state; or

(d) The employment of any other method to effectuate an equitable allocation and apportionment of the taxpayer’s income.

In any instance in which a taxpayer requests or the commissioner requires the use of any of the alternative apportionment methods in this subsection, the party requesting or requiring the method shall bear the burden of proving by preponderance of the evidence in any administrative or judicial proceeding that the methods set forth in Sections 27-7-24, 27-7-24.1, 27-7-24.3, 27-7-24.5 and 27-7-24.7 do not fairly represent the extent of the taxpayer’s business activity in this state and that the proposed method more fairly represents that activity than any other reasonable method available. The alternative apportionment authority specified in this subsection is intended to be invoked only in limited and unique, nonrecurring circumstances where the standard apportionment provisions contained in the statutes and regulations produce unanticipated results that do not fairly represent the extent of the taxpayer’s business activity in this state.

(5) The commissioner shall be prohibited from assessing any penalties related to a deficiency arising from requiring the use of an alternative apportionment method under subsection (4) of this section unless the commissioner shall establish by preponderance of the evidence that the taxpayer’s method was without reasonable basis or was not in accordance with existing statutes or regulations.