N.H. Rev. Stat. Ann. § 80:85

All land use change tax assessments levied under RSA 79-A:7 shall, on the date of the change in use, create a lien upon the lands on account of which they are made and against the owner of record of the said land. Furthermore, such liens shall continue for a period of 24 months following the date upon which the local assessing officials receive written notice of the change in use from the landowner or his agent, or the date upon which the local assessing officials actually discover that the land use change tax is due and payable, and such assessment shall be subject to the real estate tax lien procedure by the tax collector prescribed by RSA 80:59.