Do you need a license to work as a plumber in New Hampshire?

Yes. In New Hampshire, plumbing work requires a master, journeyman or apprentice plumber license issued through the Office of Professional Licensure and Certification under the Mechanical Licensing Board’s rules, and a plumbing business may act as a plumber only while an officer or member holds a master plumber license. Practicing an activity that requires professional licensure without the license is unlawful practice, punishable by a fine of up to $10,000 per offense. The license requirement does not apply to a property owner or the owner’s agent working on the owner’s own single-family detached or townhouse residence, or to plumbing done in connection with installing heating, cooling, air-conditioning or water-heating systems, among other exceptions. This is RSA 153:29, 153:29-a, 153:27, 153:36, 310:13.

WhatNew Hampshire
Plumber licenseState plumber license (Mechanical Licensing Board)

Source

RSA 153:29, 153:29-a, 153:27, 153:36, 310:13

Read the statute in the New Hampshire Revised Statutes (General Court of New Hampshire): gencourt.state.nh.us.

Checked against the statute on November 13, 2026.

This is a summary of a published statute, not legal advice. Rules change, local ordinances can add to them, and the terms of a specific lease may differ. Check the citation and speak to a lawyer before acting.

How Seayora uses this rule

A contractor on Seayora keeps each license with its issuing state, its expiry date and the last four digits of its number, and the business is warned before one lapses — on the website and both phone apps. A customer finding a pro on Seayora sees whether a license is on file.

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