N.H. Rev. Stat. Ann. § 326-I:13

A license issued by the board shall expire on the September 1 following 3 years from the date of issuance. Every person licensed under this chapter who wishes to renew a license shall, on or before the expiration date, pay a fee for renewal of license to the board. The board shall notify each person licensed under this chapter of the date of expiration of such person's license and the renewal fee required. The notice shall be mailed to such person's last known address as provided to the board at least 60 days in advance of the expiration of such license. Renewals are contingent upon demonstration of the licensee satisfying the requirements of this chapter.