N.H. Rev. Stat. Ann. § 409:8

Except as otherwise provided in RSA 409:5-a and 5-b, any life insurance company authorized to do business in this state may file with the insurance commissioner a written notice of its intention to comply with the provisions of this chapter on and after a specified date prior to January 1, 1948. After the filing of such notice, then upon such specified date, which shall be the operative date of this chapter for such company, this chapter shall become operative with respect to policies issued after such date by such company. As to such companies making no such election, the operative date of this chapter shall be January 1, 1948.