New Hampshire · Plumbing licensing · official-source guide
New Hampshire licenses plumbers individually through the Mechanical Safety and Licensing Board inside the Office of Professional Licensure and Certification, under RSA 153:27 to 153:36. It issues apprentice, journeyman and master plumber licenses, and separately licenses the business entity. A master plumber license takes 8,000 hours, 600 training hours, six months as a journeyman and a 75 percent exam.
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Verify a licenseVerified against agency sources on 2026-09-11. Rules and fees change; confirm with the named authority before relying on this guide.
New Hampshire licenses the individual plumber. The board sits inside the Office of Professional Licensure and Certification at 7 Eagle Square, Concord, New Hampshire 03301, reachable at 603-271-2152. OPLC lists the board as issuing licenses for gas fitters, oil heating technicians, plumbers, water treatment technicians and heating equipment installers. The board has two names in primary sources and both are current. RSA 153:27, paragraph I, defines Board as the mechanical licensing board established in RSA 153:27-a, and RSA 153:27-a itself is headed Mechanical Licensing Board. RSA 153:34, paragraph V, amended effective July 1, 2025, refers to the mechanical safety and licensing board. OPLC publishes the board and its fee schedule under the name Mechanical Safety and Licensing Board. Both names appear in the statute, so both are reported here rather than one being chosen. Anyone searching for the old law will hit a dead end. RSA chapter 329-A, Plumbers and Plumbing, is marked repealed, and RSA chapter 330, Plumbers, is repealed section by section. Plumbing licensure now lives in the Mechanical Licensing subdivision of RSA 153, sections 153:27 through 153:36, alongside fuel gas fitting. RSA 153:27-a places the board as a unit within OPLC. Its five appointed members include two licensed journeymen or master plumbers actively working in the trade, one licensed fuel gas fitter, one certified heating equipment installer or service person, and one public member.
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New Hampshire licenses at both levels, and they are separate credentials with separate fees. RSA 153:29, paragraph II, lists what a license may carry: hearth system installation and service technician, fuel gas installation technician, fuel gas service technician, fuel gas piping installer, fuel gas trainee, domestic appliance technician, master plumber, journeyman plumber and apprentice plumber. Paragraph III states that no licensee shall engage in any activity not covered by his or her specialty license. RSA 153:27, paragraph XII, defines master plumber as any person, firm, corporation or limited liability company that, as a business, hires or employs a person or persons to do plumbing work, or without hiring anyone does that work as a principal business or auxiliary to one for its own account. Paragraph X defines journeyman plumber as a person who customarily performs plumbing and drainage work under the direction of a master plumber. Paragraph XV defines plumbing apprentice and caps the number at two per licensee. The company needs its own license. RSA 153:29-a lets OPLC license a business entity where an officer, member, managing member or designee holds an active master plumber or fuel gas fitting license. Mec 302.05 makes it mandatory: all business entities, corporations, partnerships, limited liability companies, sole proprietors and limited liability partnerships performing fuel gas fitting or plumbing in New Hampshire shall be licensed and registered with the Secretary of State, or registered as a foreign entity if out of state. Mec 302.09 adds that a master plumber is deemed qualified as a journeyman plumber.
RSA 153:27, paragraph XIV, defines plumbing as the practice, materials and fixtures used in installing, maintaining, extending and altering all piping, fixtures, plumbing appliances and plumbing appurtenances within or adjacent to any structure, in connection with sanitary drainage or storm drainage facilities, venting systems, and public or private water systems. Then it draws a line most states do not. For the purposes of this subdivision, the term plumbing shall not apply beyond the first fitting beyond the foundation wall of the building or 5 feet of pipe from the building. Work past that point is outside the licensed definition. The exemptions in RSA 153:36 matter just as much to a contractor deciding what to bid. Paragraph VII states that the plumbing license requirements do not apply to any person or business entity performing plumbing in connection with the installation of any heating, cooling, air conditioning or domestic water heating system, whether solar, oil, gas or electric, or the installation and servicing of water treatment systems or swimming pools. Those exempt persons must still perform the work in accordance with applicable technical standards. Paragraph IV exempts employees of public drinking water systems and certified public water system operators, limited to testing, maintenance, repair, replacement and installation of the water meter, meter horn and backflow prevention devices directly adjacent to the distribution system. Paragraph V exempts an ASME-certified welder joining pipe under the direct supervision of a licensed fuel gas fitter or master plumber.
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Mec 305.01, paragraph (b), sets two routes to a journeyman plumber license and an applicant needs one of them. The first route runs through an apprenticeship. The applicant must be of good character and professional competence and must hold an apprenticeship completion certificate issued by the United States Department of Labor or by the sponsoring plumber who sponsored the apprenticeship. The applicant must show completion of a minimum of 600 hours of educational training covering a named list: plumbing systems drainage, basic and advanced plumbing theory, reading and interpretation of plumbing plans and drawings, plumbing systems venting, installation and protection of the potable water supply, proper material selection, backflow installation and protective devices, commercial kitchen design, system sizing and fixture calculations, accessibility requirements, testing and disinfecting, adopted plumbing codes, plumbing code administration including required permits and inspections, and New Hampshire statutory and regulatory law governing plumbing. And the applicant must show a minimum of 8,000 working hours of on-the-job experience in the trade relevant to plumbing as described in RSA 153:27, paragraph XIV. The second route is for someone already licensed elsewhere. An applicant who demonstrates previous licensure as a journeyman plumber in any other state or jurisdiction may sit the journeyman examination and pass it by answering at least 70 percent of the questions correctly. Mec 302.02 sets the age floor: no individual plumbing license to anyone under 18, and no apprentice or trainee license to anyone under 16. Mec 306.03 lets a person registered as both a plumbing apprentice and a fuel gas trainee accrue field experience hours concurrently.
Mec 305.01, paragraph (a), is short and strict. A person is eligible for initial licensure as a master plumber if they are of good character and professional competence, have held a New Hampshire journeyman plumber license for at least 6 months, pass the master plumber examination, and answer at least 75 percent of the questions correctly. The good character test has a specific element: being a journeyman plumber without a history of consumer complaints resulting in any disciplinary sanctions by the board within the past year. Six months is the shortest step up to a master license of any state that requires a journeyman license first, and it is worth reading precisely. The clock runs on the New Hampshire journeyman license, not on years in the trade generally. The 8,000 hours are spent before the journeyman license, not after it. The master examination covers the same fourteen subject areas listed for journeyman training, from plumbing systems drainage and venting through backflow devices, commercial kitchen design, system sizing and fixture calculations, accessibility requirements, and New Hampshire statutory and regulatory law governing plumbing. Mec 305.01(a)(3) states the examination consists of multiple choice questions on those topics. Mec 302.12 handles out-of-state applicants at any level. An out-of-state licensee is eligible for the licensing examination in plumbing and fuel gas fitting on proof of licensure in the state where the applicant claims to have worked, and must still comply with the prerequisites for the level of licensure sought regarding on-the-job experience or its approved educational equivalent.
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RSA 153:29, paragraph I, puts the nature of the examinations in the board's hands, requiring an affirmative vote of at least four appointed members to establish them by rule, and allows the board to use an outside organization it approves. Mec 308.02 sets the standards any testing organization must meet to be approved by OPLC. The applicant must submit a short statement of the specialty license, copies of exams demonstrating the validity of the questions against the adopted codes and standards and the Mec rules, and the testing administration procedure. That procedure is specified: exams consisting of a mixture of multiple choice, true or false, fill in the blank and work sheet calculations; exams consisting of no less than 100 questions; and for licensing administration a passing score of not less than 70 percent unless otherwise specified in the Mec rules. The master plumber examination is where the rules specify otherwise. Mec 305.01(a)(4) requires at least 75 percent on the master examination, while Mec 305.01(b)(4)(c) sets 70 percent for the journeyman examination taken by a previously licensed out-of-state applicant. Mec 308.02 also requires evidence of exam integrity, including that tests are secured in a locked cabinet when not in use. Mec 308.01 governs the training side. The board approves all educational programs for content, continuity and applicability, and a provider seeking approval submits its curriculum, educational material, delivery method, quizzes and chapter exams, proof of exam proctoring, and instructor biographies.
OPLC publishes the Mechanical Safety and Licensing Board fee schedule as a single table, and the plumbing rows are these. Apprentice Plumber: application $90.00, renewal $80.00, reinstatement $90.00, certificate $20.00, verification $10.00. Journeyman Plumber: application $190.00, renewal $180.00, reinstatement $190.00, certificate $20.00, verification $10.00. Master Plumber: application $310.00, renewal $300.00, reinstatement $310.00, certificate $20.00, verification $10.00. The business side is priced separately. Mechanical Business Entity: application $250.00, renewal $250.00, reinstatement $250.00, certificate $20.00, verification $10.00. Plumber Water Treatment Business carries the same $250.00 across application, renewal and reinstatement. The adjacent endorsements a plumbing company often adds are on the same page. Fuel Gas Fitting Trainee is $90.00 to apply and $80.00 to renew. Fuel Gas Fitter is $190.00 to apply and $180.00 to renew. Domestic Appliance Technician is $170.00 to apply and $160.00 to renew. Oil Heating Technician Certification is $50.00 to apply and $50.00 to renew. A master plumber running a company in New Hampshire is therefore carrying at least two licenses and two renewal fees, $300.00 for the individual and $250.00 for the entity every two years. The Mec rules point renewal and reinstatement fees to Plc 1002.25, the OPLC fee rule, rather than restating amounts.
RSA 310:8, paragraph II, makes licenses issued by OPLC valid for 2 years from the date of issuance, except apprentices licensed for one year under rules adopted pursuant to RSA 541-A. The same paragraph states that these licensing terms supersede any conflicting terms in a statute administered by a board listed in RSA 310:2. Mec 402.01 sets the date. Individual mechanical licenses, master plumber and journeyman plumber included, expire every 2 years on the last day of the month the license was issued. Mec 402.02 applies the same rule to mechanical business entity licenses, and RSA 153:29-a, paragraph II, independently expires business entity licenses every 2 years in accordance with RSA 310:8. RSA 310:8, paragraph III, is the part that catches people. A license expires when the completed renewal application, renewal fee and supporting documents have not been filed by the expiration date, and holders of an expired license are not authorized to practice until reinstated. Expired licenses lapse one year from expiration. After that year the holder cannot renew at all and must reinstate by application, meeting the eligibility requirements in statute and board rules. Paragraph IV requires OPLC to send notice at least 2 months before expiration and states plainly that failure to receive notice does not relieve the licensee of the obligation. Mec 403.01 lists what renewal takes: the Universal Application for License Renewal, an addendum for mechanical licensing affirming continuing education for each endorsement, and the fee under Plc 1002.25.
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Mec 404.01 sets the requirement per endorsement, not per person. To be eligible for renewal, individual mechanical licensees shall complete a total of no fewer than 6 hours of continuing education for each plumbing or fuel gas fitting endorsement in every 2 year licensing cycle. That is the rule contractors miscount. A master plumber who also holds a fuel gas piping installer endorsement owes 6 hours for each, and Mec 404.03(f) closes the shortcut: no student shall receive credit for a repeated education seminar, meaning each licensee shall complete separate board approved 3 hour training sessions within their individual 2 year licensing cycle for each licensing endorsement sought. The hours must come from a board approved seminar provider teaching a board approved seminar, or from a comprehensive training session sanctioned by the board where the licensee is personally an approved provider. Mec 404.03(a) requires seminars to be no fewer than 3 contact hours each, in a classroom setting, devoted to the New Hampshire adopted codes and standards for the discipline taught, the current licensing laws and adopted rules, and time for student questions. Paragraph (e) requires each student to bring a current code book for the discipline. Paragraph (c) requires the provider to check each student's plumbing or fuel gas fitting license and a government issued photo identification. Mec 404.02 sets who may teach. A provider must have held a New Hampshire master plumbing or fuel gas service technician license for at least 3 consecutive years, or a journeyman plumber or fuel gas fitting license for 5 consecutive years, and must not be a board member or an enforcement inspector.
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There are two reciprocity routes and they sit in different statutes. RSA 153:28, paragraph V, lets the board, through OPLC, enter into reciprocity agreements permitting the licensing of fuel gas fitters and plumbers from states that have a mutual mechanical licensing reciprocity agreement with New Hampshire, for all the mechanical licenses listed in paragraph I(a), provided the board determines the other state's requirements are equivalent to or greater than New Hampshire's. RSA 310:17 is the general OPLC route, added by House Bill 594 and effective August 27, 2023. Notwithstanding any other state law, the office shall issue licenses to professionals who present evidence of an active license in good standing from another jurisdiction, in accordance with rules adopted by the executive director, provided that jurisdiction's licensing requirements are substantially similar to New Hampshire's as determined by the executive director in consultation with the boards. Applicants must undergo a criminal history records check if one is otherwise required for initial licensure in that profession. OPLC began accepting applications on this pathway on May 3, 2024 and describes what it wants: the Universal Application for Initial License, the application processing fee, verification of licensure in each jurisdiction where the applicant is licensed, which may be a printout or screen capture of the licensing board's portal showing the license is in good standing, and a criminal background check. The license must be unencumbered and in active good standing. OPLC does not publish a list of qualifying states. It states that reciprocity information is updated for each profession as rules are adopted.
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RSA 310:13 is the operative penalty and it reaches advertising directly. A person who, not being licensed or otherwise authorized to practice, advertises oneself as engaging in a profession licensed by OPLC, engages in activity requiring professional licensure, or in any way holds oneself out as qualified to do so, or calls oneself a licensed professional, is engaged in unlawful practice. After notice and an opportunity to be heard under RSA 310:10, the board may impose a fine not to exceed the amount of any gain or economic benefit the person derived from the violation, or up to $10,000 for each offense, whichever amount is greater. Each violation of unlicensed or unlawful practice is a separate offense. The statute also gives OPLC a field power. The office may request to see the license of anyone who advertises as engaging in a licensed profession, or holds themselves out as qualified, at the place of business or where the business is being conducted. The board, the Attorney General, or a prosecuting attorney of any county or municipality where the unlawful practice takes place may sue to enjoin it, and an injunction without bond is available to any board. Mec 302.01 states the underlying prohibition: no person, business entity, or any combination shall engage in the business or work as a fuel gas fitter, plumber, fuel gas trainee or plumbing apprentice unless lawfully licensed under RSA 153:27 through RSA 153:38 and the rules of that chapter.
New Hampshire writes its advertising rule in inches, and this is the rule a plumbing contractor is most likely to break without knowing it. Mec 606.01 covers vehicles. Mechanical licensees, certificate holders or business entities displaying their business name on the exterior of a vehicle, and representing services by using the terms mechanical, plumbing, heating, fuel gas or propane, shall also display the appropriate mechanical license number in legible type at least 2 inches in height, on the front left and front right side of the vehicle, or in the area where the name, offer of service, or both are displayed. Mec 606.02 covers everything else. Licensees, certificate holders or business entities using visual advertising to advertise licensed services shall display their license numbers on televised advertising, billboards, advertising in the press, visual advertising on the internet, visual advertising in movie theatres, and advertising on business cards and stationery. Where the advertising uses sound, they shall state their license numbers at least once in every instance of radio advertising, auditory television advertising, auditory advertising on the web, and auditory advertising in movie theatres. A website is visual advertising on the internet. So is a paid search ad and a social profile that offers plumbing services. Mec 607.01 lists prohibited actions alongside these. A licensee shall not allow another individual or entity to use the licensee's license for the purpose of facilitating the issuance of permits or for any other purpose, shall not subcontract plumbing work to any unlicensed individual or entity, and shall not misrepresent to customers or the public, in advertising or otherwise, the services they are properly licensed and qualified to perform.
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Two primary sources conflict on New Hampshire plumbing, and a contractor relying on either alone can be misled. The first conflict is the board's name. RSA 153:27, paragraph I, defines Board as the mechanical licensing board established in RSA 153:27-a, and the heading of RSA 153:27-a reads Mechanical Licensing Board. RSA 153:34, paragraph V, as amended effective July 1, 2025, refers to current and past licensees of the mechanical safety and licensing board. OPLC publishes the board, its directory and its fee schedule under the name Mechanical Safety and Licensing Board. Both names are in force in the same chapter. The second conflict is more practical. Mec 402.01(a) states that individual mechanical licenses expire every 2 years pursuant to RSA 153:30, paragraph I. RSA 153:30 was repealed by 2023, chapter 79, section 303, paragraph II, effective September 1, 2023. Mec 402.01(b) and Mec 402.02(b) make expired licensees subject to the provisions of RSA 153:37, paragraphs I and II. RSA 153:37 was repealed by the same 2023 act, section 303, paragraph V. The live statute is RSA 310:8, which sets the two year term and the one year lapse, and RSA 310:13, which sets the unlicensed practice penalty. RSA 310:8, paragraph II, states that its licensing terms supersede any conflicting terms established in a statute administered by a board listed in RSA 310:2. So the rules point at repealed sections, and the outcome is governed by RSA 310.
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New Hampshire has no state contractor registration, so the local layer for a plumbing company is permits rather than licensing. RSA 153:29-a, paragraph IV, states that a licensed business entity may apply for and receive a permit from any municipality in the state, and Mec 302.06 requires a licensed business entity to apply for and obtain that permit. RSA 153:35 lets the building inspection department or an officer designated by the city or town enforce the board's rules. Manchester, the largest city, asks for the license on the form. The city's plumbing permit application carries fields for License No and Exp. Date alongside the location, owner or tenant name, type of building, applicant name and description of work. It charges a nonrefundable application fee of $25.00 and states a $30 minimum fee plus the $25 application fee for a total of $55.00. Nashua prices by fixture and pipe. Its residential plumbing permit charges $9.50 per fixture, $18.00 per electric water heater, $18.00 per 100 feet of water pipe, $18.00 per 100 feet of drain, waste and vent pipe, $35.00 for a sanitary sewer connection or repair, $18.00 per pump or ejector, $40.00 for miscellaneous work and $75.00 for a reinspection, on top of a $50.00 application fee. The form states that it is unlawful for anyone to install plumbing without a license unless they are exempt, and notes the homeowner exemption for work on one's own residence.
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OPLC runs a public license verification application and gives the address as forms.nh.gov/licenseverification, describing it as the place to get information regarding licensees by individual or by profession. That search is the other half of the advertising rules. Mec 606.01 and Mec 606.02 put a license number on the truck, the website and the business card. The verification site turns that number into a status. A plumbing contractor who displays a current number is handing customers a check they can finish in under a minute, and one who displays nothing is asking them to take it on faith. RSA 153:29, paragraph IV, adds a physical obligation: the license issued shall be available for inspection on request. It is not enough to have it filed at the office. Two things a customer should check that the advertising will not tell them. First, whether the number belongs to a master plumber or a journeyman plumber, since RSA 153:29, paragraph III, bars a licensee from any activity not covered by the specialty license. Second, whether the company itself holds a mechanical business entity license, because Mec 302.05 requires one of every business performing plumbing in New Hampshire and it is a separate record from the individual's. OPLC also charges a $10.00 verification fee on the fee schedule, which is what a licensee pays to have a license verified to another jurisdiction rather than what a consumer pays to search.
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These are common details other guides publish about New Hampshire, but we could not verify them from the agency source. Confirm them directly before relying on them.
Yes, and it licenses both the person and the company. The Mechanical Safety and Licensing Board, a unit within the Office of Professional Licensure and Certification under RSA 153:27-a, issues apprentice plumber, journeyman plumber and master plumber licenses to individuals, and RSA 153:29-a plus Mec 302.05 require a separate mechanical business entity license for the business.
RSA 153, sections 153:27 through 153:36, the Mechanical Licensing subdivision. The older chapters are gone: RSA 329-A, Plumbers and Plumbing, is marked repealed and RSA 330, Plumbers, is repealed section by section. General licensing terms come from RSA 310, the OPLC chapter.
Mec 305.01(b) requires an apprenticeship completion certificate, a minimum of 600 hours of educational training covering fourteen named subject areas, and a minimum of 8,000 working hours of on-the-job experience relevant to plumbing as defined in RSA 153:27, paragraph XIV.
Six months. Mec 305.01(a) requires the applicant to have held a New Hampshire journeyman plumber license for at least 6 months, to be of good character with no disciplinary sanctions from consumer complaints in the past year, and to pass the master plumber examination with at least 75 percent.
75 percent on the master plumber examination under Mec 305.01(a)(4). The journeyman examination taken by a previously licensed out-of-state applicant requires 70 percent under Mec 305.01(b)(4). Mec 308.02 sets a general floor of no less than 70 percent and requires approved exams to have no fewer than 100 questions.
OPLC publishes apprentice plumber at $90.00 to apply and $80.00 to renew, journeyman plumber at $190.00 and $180.00, and master plumber at $310.00 and $300.00. A mechanical business entity is $250.00 to apply and $250.00 to renew. Certificates are $20.00 and verifications $10.00.
Every two years. RSA 310:8, paragraph II, sets a two year term, and Mec 402.01 expires individual licenses on the last day of the month the license was issued, two years out. Apprentices may be licensed for one year. An expired license lapses one year after expiration and can then only be reinstated, not renewed.
Mec 404.01 requires no fewer than 6 hours for each plumbing or fuel gas fitting endorsement in every 2 year cycle. Mec 404.03(f) bars credit for a repeated seminar, so a licensee with two endorsements takes separate board approved 3 hour sessions for each.
Two routes. RSA 153:28, paragraph V, lets the board enter mutual reciprocity agreements with states whose requirements are equivalent or greater. RSA 310:17, effective August 27, 2023, requires OPLC to license applicants holding an active license in good standing from a jurisdiction with substantially similar requirements. OPLC publishes no list of qualifying states.
Mec 606.01 requires the mechanical license number in legible type at least 2 inches in height, on the front left and front right side of the vehicle or wherever the name or offer of service appears, whenever the business name is on the exterior and the words mechanical, plumbing, heating, fuel gas or propane are used.
Yes. Mec 606.02(a) requires license numbers on visual advertising including advertising on the internet, televised advertising, billboards, press advertising, movie theatre advertising, business cards and stationery. Paragraph (b) requires the number spoken at least once in radio, auditory television, web audio and movie theatre audio advertising.
RSA 310:13 treats advertising oneself as engaging in a licensed profession without a license as unlawful practice. After notice and a hearing, the board may impose a fine not to exceed the gain derived from the violation or up to $10,000 for each offense, whichever is greater, and each violation is a separate offense.
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