A New Hampshire tenant may not be able to change their own locks unless their lease specifically allots them that power. If they are able to do so, a New Hampshire tenant is always advised to seek permission in advance and establish a plan to provide their landlord with a new spare key. New Hampshire tenants can get their landlord to change their dwelling’s locks on their behalf, but only if they provide documentation of their status as a domestic violence victim.
The information for this answer was found on our New Hampshire Landlord Tenant Rights answers.