N.H. Rev. Stat. § 5-C:23

I. An application for filing an amended birth record in the case of a legitimation shall be made by a parent on a legitimation of child form pursuant to RSA 5-C:22 and submitted to the clerk of the city or town where the birth occurred. II. Upon receipt of a legitimation of child form and a certified copy of the parent's marriage record, or in accordance with procedures outlined in RSA 457:42 and RSA 460:29, the clerk of the city or town where the birth occurred shall prepare an amended birth record. III. The following procedures shall be followed if a legitimation case is settled by the court pursuant to RSA 460:29: (a) A certified copy of the court order shall be presented by the parents to the clerk of the city or town where the birth occurred. (b) The legitimation form shall be prepared pursuant to RSA 5-C:22 and filed by the clerk of the city or town with a notation on the form indicating that the court order has been the basis of the action under RSA 460:29. (c) The birth record shall then be processed as specified in RSA 5-C:87, and amended by adding information to the record concerning the father. IV. The clerk of the city or town shall prepare the amended birth record in accordance with RSA 5-C:89, adding the information concerning the father. V. The court order and the legitimation of child form shall be retained permanently by the clerk of the city or town on the form appropriate for the year of birth pursuant to RSA 5-C:86.