N.H. Rev. Stat. Ann. § 214:5-b

A nonresident full-time student in a public or private high school, postgraduate program, or postsecondary educational institution in this state, may purchase a nonresident student license for hunting or fishing issued under the provisions of title XVIII, if qualified for such license, at the fee charged to a resident for the respective license. For purposes of this paragraph, a full-time student in a postsecondary educational institution means a student who is registered for at least 12 credit hours per semester. A nonresident full-time student shall, when requested, show proof of his or her status by furnishing a valid student identification card.