N.H. Rev. Stat. § 477:18
Every conveyance or devise of real estate made to 2 or more persons shall be construed to create an estate in common and not in joint tenancy, unless it shall be expressed therein that the estate is to be holden by the grantees or devisees as joint tenants, or to them and the survivor of them, or unless other words are used clearly expressing an intention to create a joint tenancy. The addition, following the names of the grantees in the granting clause of a deed or devise, of the words "as joint tenants with rights of survivorship" or "as tenants by the entirety" shall constitute a clear expression of intention to create a joint tenancy.
RSA 477:18
RS 129:2. CS 135:2. GS 121:14. PS 137:14. PL 213 :17. RL 259:17. 1951, 178:11. RSA 477:18. 1959, 264:2, eff. Nov. 13, 1959.