N.C. Gen. Stat. § 105-163.16: Overpayment refunded.

If the amount of wages or compensation withheld at the source under this Article exceeds the tax imposed by Article 4 of this Chapter against which the withheld tax is credited under G.S. 105-163.10, the excess is considered an overpayment by the employee or contractor. If the amount of estimated tax paid under G.S. 105-163.15 exceeds the taxes imposed by Article 4 of this Chapter against which the estimated tax is credited under the provisions of this Article, the excess is considered an overpayment by the taxpayer. An overpayment shall be refunded as provided in Article 9 of this Chapter. (1959, c. 1259, s. 1; 1967, c. 702, s. 2; 1973, c. 476, s. 193; c. 903, s. 3; 1975, c. 74, s. 2; 1979, c. 801, s. 71; 1981 (Reg. Sess., 1982), c. 1223, s. 1; 1983, c. 663, s. 2; c. 865, s. 1; 1985, c. 443, s. 3; 1987 (Reg. Sess., 1988), c. 1063, s. 2; 1989, c. 728, s. 1.45; 1989 (Reg. Sess., 1990), c. 814, s. 23; 1991, c. 45, s. 22; 1993, c. 315, s. 2; 1997-109, s. 2.)