Notwithstanding any other provisions of the general laws, any banking institution whose business activities are taxable within and outside of this state and whose activities are limited to those described in Section 2(c)(2)(F) of the Bank Holding Company Act ( 12 U.S.C. § 1841(c)(2)(F) ) may elect the allocation and apportionment method for the taxpayer's net income provided for in this section. The election, if made, shall be irrevocable for successive periods of five (5) years. All net income derived directly or indirectly from the banking institution shall be apportioned to Rhode Island only to the extent that customers of the taxpayer are domiciled in Rhode Island. The portion of net income apportioned to Rhode Island shall be determined by multiplying the total net income from the sale of the services by a fraction determined in the following manner:
R.I. Gen. Laws § 44-11-14.3