N.C. Gen. Stat. § 44A-24.4
A lien authorized by this Part attaches to the commercial real estate only when the lien claimant files a timely notice of the lien conforming to the requirements of G.S. 44A-24.5 and this section in the office of the clerk of superior court. A notice of lien is timely if it is filed after the claimant's performance under the written agreement for broker services and before the conveyance or transfer of the commercial real estate which is the subject of the lien, except that in the case of a lease or transfer of a nonfreehold interest, the notice of a lien shall be filed no later than 90 days following the tenant's possession of the commercial real estate or no later than 60 days following any date or dates set out in the written agreement for broker services for subsequent payment or payments. When a notice of a lien is filed more than 30 days preceding the date for settlement or possession set out in an offer to purchase, sales contract, or lease, which establishes the broker's claim of performance, the lien shall be available only upon grounds of the owner's breach of the written agreement for broker services.
N.C. Gen. Stat. § 44A-24.4