In the case of every corporation carrying on business both within and outside of this state, its entire gross earnings from its operation for the preceding calendar year, or for the portion of the year that the corporation has carried on business within this state, shall be apportioned to this state as follows:
(1) In the case of an express corporation carrying on its business on steamboats, steam or electric railroads, or street railways, and in the case of a corporation whose principal business is a steamboat or ferryboat business as a common carrier, the total amount of gross earnings from all sources within this state for the calendar year or portion thereof next preceding;(2) In the case of a common carrier steam or electric railroad or street railway corporation a proportion as the total mileage of tracks operated by the corporation for steam or electric railroad or street railway purposes within this state, exclusive of sidings and turnouts, on December 31 next preceding, bears to the total mileage of tracks then operated by the corporation for these purposes, both within and outside of this state;(3) In the case of any corporation operating as a common carrier dining, sleeping, chair, or parlor car corporation, but not in the case of a public steam or electric railroad or street railway corporation operating cars as a part of or incidental to its railroad or railway business within this state, a proportion as the number of miles the cars were operated in this state during the year ending December 31 next preceding bears to the total number of miles the cars were then operated for these purposes both within and outside of this state;(4) In the case of a public service telegraph, cable, or telecommunications corporation, or corporation which is manufacturing, selling, distributing and/or transmitting to the public currents of electricity to be used for light, heat, or motive power, the total amount of gross earnings within this state for the calendar year; provided, however, that gross earnings from providing mobile telecommunications services shall be apportioned to this state where the customer's primary place of use, as determined in accordance with the mobile Telecommunications Sourcing Act (4 U.S.C. §§ 116- 126), is within this state.(5) In the case of a corporation whose principal business is manufacturing, selling and/or distributing to the public illuminating or heating gas or water, a proportion as the total miles of mains operated by the corporation within this state on December 31 next preceding bears to the total mileage of mains or wires operated by the corporation both within and outside of this state;(6) In any case to which these proportions are not equitably applicable, in the proportion that is equitable.R.I. Gen. Laws § 44-13-10
P.L. 1942, ch. 1212, art. 6, § 5; G.L. 1956, § 44-13-10; P.L. 1983, ch. 264, § 1; P.L. 1985, ch. 181, art. 62, §1; P.L. 1997 , ch. 357, § 8; P.L. 2002 , ch. 65, art. 16, § 8.