N.C. Gen. Stat. § 22C-5: Late payments to bear interest.

Should any periodic or final payment to a subcontractor be delayed by more than seven days after receipt of periodic or final payment by the contractor or subcontractor, the contractor or subcontractor shall pay his subcontractor interest, beginning on the eighth day, at the rate of one percent (1%) per month or a fraction thereof on such unpaid balance as may be due. (1987 (Reg. Sess., 1988), c. 946.)