N.H. Rev. Stat. § 5-C:22

I. Unless the legitimation is by court order, each parent shall complete a legitimation of child form with the following: (a) Information regarding the child, mother, and natural father, including: the name of the child as originally recorded; date and place of birth; maiden name of the natural mother; mother's social security number; mother's city or town of residence; full name of the child, full name of the natural father; date of birth of the natural father; state or foreign country of birth of the natural father; natural father's social security number; and current mailing address of the parents. (b) The signature of the natural father and the mother. (c) The city or town and county where the affidavit was signed. (d) The signature of the notary public or justice of the peace with the expiration date of commission, the date signed, and sealed if applicable. (e) Indication as to whether the certificate of marriage was presented to the clerk of the town or city. (f) The date received by the clerk of the town or city. (g) The date the new record was made. (h) The signature and city or town of the clerk. II. When the mother or natural father or both are under the age of 18, each signature shall be accompanied by the notarized signature of a parent or guardian unless the legitimation is by court order.