N.C. Gen. Stat. § 45-71
Upon payment of all the obligations secured by a security instrument which conforms to the requirements of this Article and upon termination of all obligation to make advances, and upon written demand made by the maker of the security instrument, his successor in interest, or anyone claiming under him, the holder of the security instrument is hereby authorized to and shall make a written entry upon the security instrument showing payment and satisfaction of the instrument, which entry he shall date and sign. When the security instrument secures notes, bonds, or other undertakings for the payment of money which have not already been entered on the security instrument as paid, the holder of the security instrument, unless payment was made to him, may require the exhibition of all such evidences of indebtedness secured by the instrument marked paid before making his entry showing payment and satisfaction.
N.C. Gen. Stat. § 45-71