N.C. Gen. Stat. § 105-449.137: Liability for and payment of the tax.

(a) Liability. - A bulk end-user or retailer that stores highway and nonhighway alternative fuel in the same storage facility is liable for the tax imposed by this Article. The tax payable by a bulk end-user or retailer applies when fuel is withdrawn from the storage facility. The alternative fuel provider that sells or delivers alternative fuel is liable for the tax imposed by this Article on all other alternative fuel.

(b) Payment. - The tax imposed by this Article is payable when a return is due. A return is due on the same date as a monthly return due under G.S. 105-449.90. A monthly return covers liabilities that accrue in the calendar month preceding the date the return is due. A return must be filed with the Secretary and must be in the form and contain the information required by the Secretary. (1995, c. 390, s. 3; 1997-60, s. 24; 2006-162, s. 15(d); 2008-134, s. 56.)