N.C. Gen. Stat. § 31-32

(1) At the time of application for probate of any will, and the probate thereof in common form, or at any time within three years thereafter, any party interested in the estate, may appear in person or by attorney before the clerk of the superior court and enter a caveat to the probate of such will; Provided that if any person entitled to file a caveat be within the age of 18 years, or incompetent as defined in G.S. 35A-1101(7) or (8), then such person may file a caveat within three years after the removal of such disability.

(2) The caveat shall be filed in the decedent's estate file. The clerk of superior court shall give notice of the filing by making an entry upon the page of the will book where the will is recorded, evidencing that the caveat has been filed and giving the date of such filing.

(3) If a will has been probated in solemn form pursuant to G.S. 28A-2A-7, any party who was properly served in that probate in solemn form shall be barred from filing a caveat.