N.H. Rev. Stat. Ann. § 231:170

In connection with the transfer of all or any interest in any poles, structures, conduits, cables, or wires, the transferor may by appropriate assignment transfer his or its license to maintain the same and the transferee shall be entitled to have and exercise such license to the extent necessary for his or its use of the transferred property, upon recording such assignment with the clerk of the town in which said property is situated.