N.H. Rev. Stat. § 231:124
All assessments under the provisions of RSA 231:120 and 122 shall create a lien upon the lands on account of which they are made, which shall continue until one year from October 1 following the assessment, and, in case an appeal has been taken and the assessment has been sustained in whole or in part upon such appeal, until the expiration of one year from such decision, whichever is later. Such assessments shall be subject to the interest and such other charges as are applicable to delinquent taxes. In the event that the assessments are payable over a period of years, then the assessment shall be prorated on an annual basis and the lien on said lands shall attach annually.
RSA 231:124
RSA 252-A:11. 1969, 493:1. 1981, 87:1, eff. April 20, 1981.