N.H. Rev. Stat. § 541:19
Any order of the court suspending an order of the public utilities commission fixing rates, fares, charges, or prices shall, among other things, provide that the public utility affected by the order suspended shall keep such accounts as shall suffice to show the amount being collected by such public utility, pending the appeal, in excess of the amounts which it would have collected if the order or decree of the commission had not been suspended, and shall provide such means as the court shall determine to secure the prompt repayment of all excess rates, fares and charges over and above the rates, fares and charges which shall finally be determined to be reasonable and just.
RSA 541:19
1913, 145:18. PL 239 :19. 1937, 107:32; 133:93. RL 414:21. 1951, 203:17, eff. Sept. 1, 1951.