N.C. Gen. Stat. § 62-143

The schedule of rates fixed by statute or under this Article, in suits brought against any public utility involving the rates of a public utility or unjust discrimination in relation thereto, shall be taken in all courts as prima facie evidence that the rates therein fixed are just and reasonable. Any such schedule when certified by a clerk of the Commission as a true copy of a schedule on file with the Commission shall be received in all courts as prima facie evidence of such schedule without further proof, and, if the clerk certifies that said schedule has been approved by the Commission, as prima facie evidence of such approval.