How to check a contractor's license in New Hampshire

Who licenses what in New Hampshire

The Mechanical Safety and Licensing Board's page lists "Gas Fitters", "Oil Heating Technicians", "Plumbers" and "Water Treatment Technicians" under "Who We Regulate" (read 25 October 2026). OPLC's License Lookup lists the occupations on its online verification; "Electrician", "Home Inspector" and "Manufactured Housing Installer" are on it, and plumbers and gas fitters were not when we checked.

How to look a contractor up, step by step

1. Electrician: ask for the master electrician's name and license number. In New Hampshire a journeyman "shall be employed by a New Hampshire licensed master electrician" (RSA 319-C:2, IV), so a crew of journeymen still has a master behind it. Open OPLC's License Lookup and follow its New Hampshire Online Verification, which covers electricians, to find the master's record and expiry date. If the name does not come up, call OPLC at 603-271-2152.
2. Plumber, gas fitter or oil heat technician: ask for the license number and the license holder's name, then call OPLC customer support at 603-271-2152 (7 Eagle Square, Concord) to confirm it is active.
3. Expired licenses: OPLC's electrician FAQ says "you will need to have an active New Hampshire license to work in this state." An expiry date before your start date is a no.
4. General contractor, roofer, remodeler: there is no license to check. Ask for the addresses of recent jobs and look them up in the city's permit record; in Nashua that is the permit map linked from the Department of Building Safety page (see our Nashua permit search guide).
5. Complaints: the Attorney General's Consumer Protection Hotline is 1-888-468-4454.

Homeowner exemptions

New Hampshire lets owners do some licensed work themselves. RSA 319-C:15, II says "Nothing in this chapter shall prevent a homeowner from making electrical installations in or about a single family residence" the owner lives in or will live in. RSA 153:36 exempts a homeowner doing fuel gas fitting in their own single-family primary residence, and property owners doing their own plumbing, as long as the work follows the state code and inspection rules (RSA 153:36). The exemption is for the owner, not for an unlicensed person the owner hires: the Attorney General lists a contractor who says they can do "electrical work, inspections, plumbing" without a license as a warning sign.

Penalties for unlicensed work

RSA 319-C:15, I makes it a violation to make "electrical installations without being licensed under this chapter", and to employ unlicensed people other than apprentices. It is a misdemeanor for a natural person and a felony for any other person, such as a company (RSA 319-C). There is no penalty for unlicensed general contracting, because there is no license.

Our permit data in New Hampshire

Nashua issued 1,318 electrical permits in the last 12 months (October 2025 to September 2026) and 623 plumbing permits. The city's FAQ says "The State of New Hampshire requires a license of the person engaging in the business of either plumbing or electrical", and that trade permits (electrical, plumbing and mechanical) cannot be issued until after the building permit. The city's published permit file names no contractor, so we cannot match Nashua permits to licenses or list firms. To check whether your job's permit was finaled, ask the Department of Building Safety, 603-589-3080.

Red flags on a New Hampshire job

• An electrician who cannot give a license number, or whose name does not come up in OPLC's online verification.
• A general contractor who says they will do the wiring or plumbing themselves without a license; the Attorney General lists this among its scam warning signs.
• A down payment request over 50% of the price, or cash or Zelle/Venmo only; both are on the Attorney General's list.
• No written contract. The Attorney General's advice: "Always have a written contract before any work is done or any payment made."
• A contractor who asks you to pull the permit as the owner when they are doing the work.