N.C. Gen. Stat. § 58-72-50

The approval of all official bonds taken or renewed by the board of commissioners shall be recorded by the clerk to the board. Each bond shall be acknowledged by the parties thereto or proved by a subscribing witness, before the chairman of the board of commissioners, or before the clerk of the superior court, and filed with the clerk of the superior court with the approval of the commissioners endorsed thereon and certified by the chairman of the board of commissioners. Provided that an official bond executed as surety by a surety company authorized to do business in this State need not be acknowledged upon behalf of the surety when that bond is executed under seal in the name of the surety by an agent or attorney-in-fact by authority of a power of attorney duly recorded in the office of the register of deeds of that county.