How to Start a Plumbing Business in Maine: Plumbers' Examining Board Licenses, $200 Master and Journeyman Fees and the Title 30-A 4215 Permit Exemption

If you want to know how to become a plumber in Maine, the process has three parts: getting the right Plumbers' Examining Board license, confirming whether a specific job needs a license or only a permit, and forming the business that will bid and invoice the work. This guide walks through each part with the fees and deadlines that apply in 2026, so you can plan the paperwork before you buy tools or a truck.

This article is informational content, not legal or tax advice. Licensing rules, fees and permit categories can change. Confirm every figure with the agency named before you pay or sign a contract, and talk with a licensed attorney or certified public accountant (CPA) before you choose a business structure, especially if you will have partners, employees or more than one entity.

The Short Answer

To work as a plumber for pay in Maine, you generally need a license from the Plumbers' Examining Board under 32 MRSA chapter 49. The Maine plumbing license path runs from trainee to journeyman to master, and a separate journeyman-in-training license is also available. Towns cannot license plumbers. Instead, a local plumbing inspector issues permits for certain plumbing work under 30-A MRSA 4215. Your business entity is a separate filing: an LLC or corporation files with the Secretary of State, while a sole proprietor who uses a trade name files with the municipal clerk.

What You Need Before You Start

Gather these items before you file anything. A missing document usually means a rejected application or a delayed filing.

• Work history records. Keep a dated log of every hour you work under a licensed plumber, since your years as a trainee or journeyman control when you can sit for the master exam.
• A payment method for the license fee and the $21 background check. The background check applies to each new license you receive.
• A business name that meets Maine rules. An LLC name must include “limited liability company,” “LLC,” “L.L.C.,” “L.C.” or “LC” under 31 MRSA 1508.
• Form MLLC-1 if you want to reserve a name for 120 days. The reservation costs $20.
• Form MLLC-6, the Certificate of Formation for an LLC, with the $175 filing fee. Maine does not accept formation documents online, so you print the PDF and mail or deliver it with payment.
• A registered agent. Every Maine LLC must maintain one. If you use a noncommercial agent, that agent needs a physical street address in Maine, not a P.O. box.
• Form ASUM-5 with its $125 fee if your LLC or corporation operates under a name other than its legal name. Sole proprietors instead file a sworn assumed-name certificate with the municipal clerk, and that municipal fee is set locally.
• A calendar with the June 1 annual report deadline, which carries an $85 fee every year.

Step 1: Choose the License Level That Matches Your Experience

The Board issues four license types. The fees below are the 2026 amounts. Each new license also carries the $21 background check.

License	Fee	Eligibility and notes
Trainee	$100	Entry level. Trainees work under the supervision of a licensed master or journeyman.
Journeyman	$200	Requires 2 years as a trainee.
Master	$200	Exam eligibility after 1 year as a journeyman or 4 years as a trainee.
Journeyman-in-training	$200	A four-year license that cannot be renewed. Confirm eligibility with the Board.

Licenses renew every two years. Renewal fee amounts are not part of this summary, so check the Board's current schedule before you calendar them. A renewal filed up to 90 days after expiration carries a $50 late fee. Do not let a license lapse and keep working, because unlicensed practice carries serious penalties, covered in the mistakes section below.

Step 2: Confirm Whether the Job Needs a License or a Permit

This is the step most new contractors skip, and it decides whether the license question applies to a specific job. Under 30-A MRSA 4215, plumbing work requires a permit from the local plumbing inspector. The permit categories named in the statute include installing plumbing into a building, subsurface wastewater systems and seasonal conversions. The license requirement does not reach any activity that needs no permit under that section.

Two points follow. First, the license and the permit are separate requirements. A town permit does not replace your state license, and a state license does not replace the permit. Second, a town cannot add its own plumber license, because 32 MRSA 3302 bars municipalities from licensing plumbers. Whatever a town requires, it requires through the inspector's permit process. On any unusual job, ask the inspector for the answer in writing before you bid.

Step 3: Train Under Supervision and Track Your Hours

Most new plumbers start as trainees. A master or journeyman may supervise at most 3 trainees. If a supervisor already has three trainees, a fourth trainee needs a different supervisor. Keep a log with the supervisor's name, license number, dates and task types so you can produce it if the Board asks.

Several neighboring trades have narrower rules that matter when their work overlaps with plumbing. Oil burner technicians and propane or natural gas installers may make hot and cold water connections to existing piping in the same room. A master plumber does not need a Water Well Commission license to install pumps (see 4700-J). For a heat pump water heater, check with the Plumbers' and Electricians' Examining Boards before you quote the job, because the answer depends on the specific work.

Step 4: Apply, Pay the Fees and Keep the License Active

Submit your application to the Plumbers' Examining Board, part of the Department of Professional and Financial Regulation's Office of Professional and Occupational Regulation, with the license fee and the $21 background check. Confirm the current form and submission method with the Board before you send payment. Exam fees are not part of the figures in this article, so confirm them with the Board as well.

Once licensed, set a reminder well ahead of your renewal date. The license renews every two years, and the $50 late fee applies only within the 90 day window after expiration.

Step 5: Form the Business Entity

Your entity choice affects filings, cost and taxes, so settle it before you paint a company name on a van.

Sole proprietor

A sole proprietor who works under their own name needs no state formation filing. If you use a trade name, file a sworn assumed-name certificate with the clerk of the city or town where the business is carried on, under 31 MRSA 1. The state does not publish municipal fees, so ask the clerk for the amount.

LLC

Form MLLC-6 is the Certificate of Formation, filed under 31 MRSA 1531, with a $175 filing fee. The Secretary of State's pages state that corporate filings take 2 to 7 business days. That figure has changed over time, so confirm it on the agency's current pages before you set a start date. Expedited handling costs $50 for 24 hour service or $100 for immediate service. Availability depends on staffing when you submit, and the Bureau notes delays during periods of high expedited volume.

Every LLC must appoint and continuously maintain a registered agent. Appointments and changes are filed on Form CLKRA-3 for $35. After formation, the annual report (Form MLLC-13) costs $85 and is due June 1 each year. Your first report is due between January 1 and June 1 of the year after formation. Maine has no LLC franchise tax and no separate LLC annual tax, so that $85 is the only recurring state filing charge.

Corporation

Articles of Incorporation (Form MBCA-6) cost $145 and are filed under Title 13-C, the Maine Business Corporation Act. Corporations pay the same $85 annual report. Many small plumbing businesses start as LLCs, but whether a corporation fits your situation is a question for a CPA.

Step 6: Handle Local, Income and Sales Tax Obligations

Maine issues no general statewide business license, and no general town license either. Filing your entity or assumed name is a filing, not a license. Licensing is by activity. Each of Maine's 482 organized municipalities (23 cities, 430 towns and 29 plantations) sets its own ordinances and fees, and the state's 16 counties license nothing for ordinary businesses. Ask your municipal office whether any local license applies to your work. The state's free Business Answers assistant at https://maine.gov/businessanswers can help identify any state permits or licenses that apply to your activity.

On income tax, an LLC is taxed by default as a pass-through, so members report income on Maine individual returns at graduated rates of 5.8% to 7.15%. For tax years beginning on or after January 1, 2026, a 2% surcharge applies to Maine taxable income above $1,000,000 for single filers, $750,000 for married filing separately, or $1,500,000 for married filing jointly or head of household. An LLC that elects corporate treatment pays Maine corporate income tax at 3.5% to 8.93%.

On sales tax, Maine's general rate is 5.5%. The list of taxable services is closed, so a service that is not on the list is not subject to sales tax. Whether plumbing labor or any part of your work appears on that list is a question for Maine Revenue Services at https://www.maine.gov/revenue/. Resolve it before you quote customers, because the answer decides whether your invoices must show tax.

Common Mistakes to Avoid

• Looking for a town plumbing license. Towns cannot license plumbers under 32 MRSA 3302. Your state license is the one that governs your work, and the town's role runs through the permit.
• Assuming a permit replaces the license. The license requirement does not reach activity that needs no permit under 30-A MRSA 4215. Confirm which side a job falls on before you start.
• Supervising more than 3 trainees. A master or journeyman may supervise at most 3 trainees, so a fourth trainee needs another supervisor.
• Working without a license. Unlicensed practice carries a civil penalty of $1,000 to $5,000 per violation, and it is also a crime under 10 MRSA 8003-C.
• Forgetting the background check. The $21 charge applies to each new license, so budget for it at every step up the ladder.
• Letting the license expire. The $50 late fee applies within 90 days after expiration. Plan for renewal every two years.
• Using a P.O. box as a noncommercial registered agent address. The agent needs a physical street address in Maine.
• Choosing an LLC name without the required ending. Under 31 MRSA 1508, the name must include one of the accepted designations.
• Missing the June 1 annual report. The $85 report is due every year. The first one falls due between January 1 and June 1 of the year after formation.
• Using a trade name without filing. Sole proprietors file with the municipal clerk, and registered entities file Form ASUM-5 with the Secretary of State.

What Results to Expect

Licensing and formation are paperwork-heavy, and your results depend on your experience, your local market and how well you manage the filings. Many new plumbers find that a clean record of supervised hours and on-time renewals makes the path to a master license more predictable, though no filing guarantees a particular timeline or volume of work. Keeping the license current, the entity in good standing and the annual report on time may help you avoid late fees, lapses and the penalties that tend to create the most avoidable cost.

Official Resources

• Maine Secretary of State, Division of Corporations, UCC and Commissions: https://www.maine.gov/sos/corporations-commissions
• Business entity search: https://apps3.web.maine.gov/nei-sos-icrs/ICRS
• Annual report online (InforME): https://apps1.web.maine.gov/cgi-bin/online/aro/index.pl
• Maine Revenue Services: https://www.maine.gov/revenue/
• Business Answers licensing assistant: https://maine.gov/businessanswers
• Maine Small Business Development Centers: https://www.mainesbdc.org/
• U.S. Small Business Administration, Maine district: https://www.sba.gov/district/maine

Before you file, call the Plumbers' Examining Board, your local plumbing inspector and the Secretary of State to confirm the figures in this guide. Maine's Small Business Development Centers can help with planning. For the tax treatment of your entity and any sales tax questions, consult a CPA, and consult an attorney for contracts and liability.