N.H. Rev. Stat. § 5-C:97

I. If the marriage license issued to the prospective bride and groom is not used for any reason, it shall be returned to the clerk of the town or city of issuance. II. If the completed marriage license has not been returned by the officiant within 30 days of the planned date of the marriage, as noted on the marriage application worksheet, or 90 days has elapsed from the date the marriage intentions were filed, the clerk of the town or city shall contact the applicants to determine whether the marriage ever took place and who officiated and contact the officiant to request the marriage license. III. If the clerk of the town or city is unable to obtain the marriage license, the clerk shall notify the division within 24 hours and contact one of the applicants to begin the process for a delayed marriage certificate as described in RSA 5-C:52. IV. In the circumstances noted in paragraph II, the clerk of the town or city shall retain the application worksheet permanently and a notation shall be made to the application stating the marriage presumably did not take place. V. All marriage worksheets shall be retained by the clerk of the town or city in accordance with the retention schedule as specified in this chapter.