N.C. Gen. Stat. § 156-126
Upon adjustment of delinquent installments of any assessment as provided herein, the payment of all delinquent installments so adjusted may be extended over a period not exceeding the life of the issue of refunding bonds, but in no event over a period exceeding 20 years. Such extension shall be made by the preparation of assessment rolls, which shall provide for the payment of installments so adjusted in equal annual installments which shall become due annually on September 1, in accordance with the original assessment, and shall bear interest at the rate of four per centum (4%) per annum from December 1 following their due date until paid. Such assessment rolls shall be prepared and filed with the sheriff and the clerk of superior court and receipts shall be prepared and the same shall be collected in the same manner as other assessments of the district.
N.C. Gen. Stat. § 156-126