§11-23-5. Apportionment of Tax Base

(a) A taxpayer subject to the tax imposed by this article and also taxable in another state shall, for the purposes of this tax, apportion its tax base to this state by multiplying its tax base by a fraction, the numerator of which is the sum of the property factor, plus the payroll factor, plus two times the sales factor, all of which shall be determined as hereinafter provided in this section, and the denominator of which is four, reduced by the number of factors, if any, having no denominator, with the sales factor counting as two factors.

(b) Property factor. — The property factor is a fraction, the numerator of which is the average value of the taxpayer's real and tangible personal property owned or rented and used by it in this state during the taxable year, and the denominator of which is the average value of all real and tangible personal property owned or rented by the taxpayer and used by it during the taxable year, which is reported on Schedule L of Federal Form 1120 (or 1065 for partnerships), plus the average value of all real and tangible personal property leased and used by the taxpayer during the taxable year.

(c) Value of property. — Property owned by the taxpayer shall be valued at its original cost, adjusted by subsequent capital additions or improvements thereto and partial disposition thereof, by reason of sale, exchange, abandonment, etc.: Provided, That where records of original cost are unavailable or cannot be obtained without unreasonable expense, property shall be valued at original cost as determined under regulations of the Tax Commissioner. Property rented by the taxpayer from others shall be valued at eight times the net annual rental rate. Net annual rental rate is the annual rental paid, directly or indirectly, by the taxpayer, or for its benefit, in money or other consideration for the use of the property and includes: