N.C. Gen. Stat. § 58-40-75
No insurer shall assume any obligation to any person, other than a policyholder or other insurers with which it is under common control or management or is a member of a market assistance program or of a joint underwriting or joint reinsurance organization, to use or adhere to certain rates or rules; and no other person shall impose any penalty or other adverse consequence for failure of an insurer to adhere to certain rates or rules. This section does not apply to mandatory or voluntary risk sharing plans established under Article 42 of this Chapter or apportionment agreements among insurers approved by the Commissioner pursuant to G.S. 58-40-95. Provided, however, that members and subscribers of statistical organizations may use the rates, rating systems, underwriting rules, or policy or bond forms of such organizations either consistently or intermittently. The fact that two or more admitted insurers, whether or not members or subscribers of a statistical organization, consistently or intermittently use the rates or rating systems made or adopted by a statistical organization, or the underwriting rules or policy or bond forms prepared by a statistical organization, shall not be sufficient in itself to support a finding that an agreement to so adhere exists, and it may be used only for the purpose of supplementing or explaining direct evidence of the existence of any such agreement.
N.C. Gen. Stat. § 58-40-75