How to Start an HVAC Business in New Hampshire

Holding a personal gas fitter license in New Hampshire does not authorize you to operate as a business. You cannot bid on contracts, advertise under a company name, or pull permits as a business entity using only your individual OPLC credential. That realization — usually triggered by a rejected permit application — is what sends most transitioning technicians into the business formation process.

The path from personal license to operating company has several layers, and the order matters.

Step 1: Register Your Business Entity With the Secretary of State

Before approaching the OPLC for a business license, you need a legal entity. Most HVAC contractors in New Hampshire form an LLC for liability protection.

File your Certificate of Formation (LLC-1) with the New Hampshire Secretary of State through the online QuickStart portal. The filing fee is $102 for online submissions. If you plan to operate under a name different from your legal LLC name, file a Trade Name Registration (DBA) for $50.

Once your LLC is approved, obtain a Federal Employer Identification Number (EIN) from the IRS website — this is free and typically issued immediately online.

Step 2: Get Your Insurance in Place

Plan for commercial general liability coverage for the business entity. If you form an LLC and perform on-site work, you also need workers' compensation coverage:

Commercial general liability insurance — the practical minimum is $1,000,000 per occurrence. This is not a statutory minimum written into the mechanical licensing rules, but it is the standard threshold that the OPLC, municipalities, and general contractors expect to see on your certificate of insurance.

Workers' compensation insurance — and this is where the most expensive compliance trap lives for new HVAC business owners.

The Workers' Comp Trap for LLC Members

Under NH RSA 281-A, a traditional sole proprietor with no employees is not required to carry workers' compensation insurance on themselves. But forming an LLC changes the equation: the state classifies all managing members as employees of the LLC.

New Hampshire allows an LLC to exclude up to three members from workers' comp coverage by filing exclusion paperwork. However, that exclusion is legally voided if the excluded member performs physical, on-site manual labor at any active construction site.

Since nearly every residential and commercial HVAC installation occurs on an active construction or renovation site, self-employed LLC members cannot legally exclude themselves in practice. Operating without coverage exposes you to Department of Labor stop-work orders and penalties of up to $2,500 per infraction plus $100 for every business day you operate without a policy.

The practical advice: budget for workers' comp as a fixed operating cost from day one if you are forming an LLC and doing on-site mechanical work.

Step 3: Apply for the OPLC Mechanical Business Entity License

With your LLC registered and insurance certificates in hand, submit the Mechanical Business Entity Initial and Renewal Application to the OPLC. The application requires:

• Your registered business entity name and Secretary of State registration number
• Designation of the qualifying license holder — the licensed individual (you, in most cases) who is legally responsible for all mechanical work performed under the entity
• Proof of commercial general liability insurance
• $250 biennial licensing fee

One significant exemption: under Mec 307.04(g), a business owner who is the sole licensee — meaning the firm employs no other licensed technicians, apprentices, or trainees — is completely exempt from the $250 business licensing fee. This exemption is voided the moment you hire or register any additional licensed personnel.

Step 4: Handle State Tax Registration

New Hampshire has no income tax or sales tax, but it does tax business profits:

• Business Profits Tax (BPT): 7.5% on gross business income exceeding $109,000
• Business Enterprise Tax (BET): 0.55% calculated on total enterprise value tax base

Register with the New Hampshire Department of Revenue Administration. A CPA familiar with NH business taxes is worth consulting here, especially for understanding the BET calculation and estimated quarterly payments.

Step 5: Set Up Municipal Relationships

Your business entity license authorizes you to operate statewide, but every job requires the applicable local mechanical or electrical permit. Before your first project, identify the building department in each municipality you plan to serve. Manchester, Nashua, Concord, and other cities each have their own permit application processes, fee schedules, and inspection requirements.

Building relationships with local building officials early — understanding their permit turnaround times, inspection scheduling, and any local code amendments — is worth more than any amount of statewide paperwork.

The Complete Sequence

The correct order, from scratch:

1. Personal gas fitter license from the OPLC (trainee → education → exam → application)
2. LLC formation with the Secretary of State ($102)
3. EIN from the IRS
4. Commercial general liability insurance ($1M minimum)
5. Workers' comp insurance (mandatory for LLC members doing on-site work)
6. OPLC Mechanical Business Entity license ($250, or exempt as sole licensee)
7. State tax registration
8. Municipal permit relationships

Skipping any step or doing them out of order creates cascading delays. The New Hampshire HVAC License Guide walks through each step with the exact forms, portals, and fee amounts so you can work through the sequence without backtracking.

See more New Hampshire guides →