(a) A corporation that provides local telephone service to low-income residential consumers at reduced rates pursuant to an order of the North Carolina Utilities Commission is allowed a credit against the tax imposed by this Part equal to the difference between the following:
(1) The amount of receipts the corporation would have received during the taxable year from those low-income customers had the customers been charged the regular rates for local telephone service and fees.
(2) The amount billed those low-income customers for local telephone service during the taxable year.
(b) This credit is allowed only for a reduction in local telephone service rates and fees and is not allowed for any reduction in interstate subscriber line charges. This credit may not exceed the amount of tax imposed by this Part for the taxable year reduced by the sum of all credits allowable, except tax payments made by or on behalf of the corporation. (1985, c. 694, s. 2; 1998-98, s. 90.)