Overview
New Hampshire licenses plumbers at the state level through the Office of Professional Licensure and Certification Mechanical Safety and Licensing Board. That means the core plumber credential is not a town-by-town license. Cities and towns still control permits, inspections, and local enforcement, but the card that says you can work as a plumber comes through OPLC and the board.
The ladder is the familiar New England model: Apprentice Plumber, Journeyman Plumber, and Master Plumber. The apprentice registration lets you train under a licensed plumber. The journeyman license is the working credential after the training period and exam. The master license is the business-facing credential for people who supervise, contract, and take responsibility for plumbing work.
I am keeping New Hampshire's hour and fee figures general because accessible official material did not publish them cleanly. The safe read is simple: register before counting experience, keep supervision records, pass the exam, then move from journeyman to master when the board accepts the record.
Apprentice, Journeyman, and Master
The apprentice registration is permission to learn the trade. It is not permission to run work alone or sell plumbing services to the public. An apprentice works under a licensed plumber and builds the documented field record that supports the journeyman application later. If you start work before the registration is active, you risk losing credit for that time because the board cares about documented supervised experience, not informal time in the trade.
The journeyman license is the individual work license. A journeyman can perform plumbing work within the scope of the license and the adopted code, but the business structure still matters.
The master license sits above that. A master plumber is the person who can take the lead responsibility for plumbing work, supervise lower tiers, and support the contracting side of the operation.
Experience and Exam
The key requirement is not a course certificate by itself. New Hampshire wants a documented training path acceptable to the board, followed by the licensing exam for the level you are applying for. Keep employer names, license numbers, dates, work categories, and apprenticeship records from the first day in the field.
For the journeyman license, the board-recognized path runs through supervised training and an exam. OPLC's live application materials control the exact documentation format, and that is the document set I would build around. Do not rely on a payroll printout alone if the application asks for signed experience or apprenticeship completion records.
The master license adds another screen: the board has to accept that the applicant has moved beyond supervised installation into the level of experience needed to supervise, plan, and be responsible for work. Expect a separate exam or board review step for that license tier.
Application Process
Start with the apprentice registration before you count your first hours. The clean path is simple: register, work under a licensed plumber, keep records, complete the training or equivalent experience that OPLC accepts, then apply for the journeyman exam. Once OPLC accepts the application, you test through the state-approved process and the license issues after every piece of the file is complete.
If you are moving into New Hampshire from another state, include official license verification from every state where you held a comparable plumbing license. A photocopy of a wallet card is useful background, but official verification is the piece licensing boards trust.
Running Plumbing Work
New Hampshire's license ladder separates learning, working, and responsible supervision. That split matters when you start bidding work. A journeyman license shows personal trade competence. A master license is the credential that supports responsibility for a plumbing operation and supervision of others.
This is also where related trades create risk. Plumbing, fuel gas fitting, oil burner work, and other mechanical scopes can touch the same job. New Hampshire regulates those scopes through OPLC, and a plumber should not assume that one card covers every connected system.
Costs and Renewal
I am not publishing New Hampshire dollar figures without a clean official fee table. Treat the fee as an application-controlled number: the amount on the OPLC form or portal at the time you file is the number that matters. That includes apprentice registration, journeyman and master applications, exams, renewals, and any late or reinstatement items.
The recurring cost is modest compared with the time cost. The real investment is supervised field experience, classroom or apprenticeship records where required, exam preparation, and keeping the license active after it issues. Renewal also keeps your record clean for permits, employment, and future master-level applications.
Out-of-State Licenses
New Hampshire has an out-of-state licensing path through OPLC, but I am not naming partner states or automatic waivers without an accessible official reciprocity list. The practical requirement is documentation. Bring official license verification, proof of how the original license was earned, exam history, and a clean description of the experience behind it.
A strong out-of-state file does two things. It shows that the license is active and in good standing, and it shows that the other state's requirements match the New Hampshire level you want. If the board does not accept equivalency, expect to document experience and sit the New Hampshire exam.
Contractors moving a business into the state should separate the individual license question from the business setup question. The person needs the correct plumbing license, and the company still needs the business registrations and local permit relationships that let it operate cleanly.
FAQ
Who licenses plumbers in New Hampshire? OPLC's Mechanical Safety and Licensing Board handles state plumbing licenses. Local jurisdictions still handle permits and inspections.
What are the main license levels? Apprentice Plumber, Journeyman Plumber, and Master Plumber. The apprentice level is supervised training, journeyman is the working license, and master is the higher responsibility tier.
Can I use an out-of-state license? You can apply through the out-of-state process, but you need official license verification and proof that your prior requirements match New Hampshire's expectations.
Why are no exact fees listed here? I did not find an accessible official fee table during research. Use the fee on OPLC's current application or portal for filing.