N.H. Rev. Stat. § 5:15-d

I. The following requirement shall apply to any registered agent required to be appointed by law for any corporation, limited liability company, limited liability partnership, limited partnership, or any other business formation or entity required to be registered with the secretary of state: if the agent is a natural person, the person shall be 18 years of age or older and be a resident of New Hampshire during all such times as the person is named as agent. II. If the agent is another registered business entity, such entity shall be in good standing with the secretary of state. For the purposes of this section, "good standing" means the registered business entity is active on the secretary's records and compliant with its legal obligation to file annual reports and/or pay annual fees as applicable, and maintain a registered agent and registered office. III. No corporation, limited liability company, partnership, or other business entity required to maintain a registered office in this state shall designate the address of a commercial postal box provider, virtual office, mail forwarding service, or any similar service as its registered office address. For the purposes of this section, "commercial postal box provider" means any business or entity primarily engaged in providing mail-receiving, forwarding, or virtual office services, including, but not limited to, those operating under private mailbox agreements or offering mail-handling services without providing a dedicated physical office space for the business entity.