What licence does your HVAC or plumbing hire need for the work you're staffing?

Start with the one federal baseline: refrigerant.

Under EPA's rules at 40 CFR 82.161, any person who could reasonably be expected to violate the integrity of the refrigerant circuit while maintaining, servicing, repairing or disposing of appliances that contain CFC/HCFC or non-exempt substitute refrigerants such as HFCs must pass an exam from an EPA-approved technician certification program.

That certification is EPA 608, and its types map to the equipment your jobs run.

Type I covers small appliances — the units fully manufactured, charged and hermetically sealed in a factory with 5 pounds or less of refrigerant, like refrigerators, window and portable ACs, PTACs, dehumidifiers and vending machines.

Type II covers medium-, high- and very-high-pressure appliances — the type that covers residential split-system AC and heat pumps.

Type III covers low-pressure appliances such as chillers, and Universal covers all three.

EPA 608 does not expire, so the card travels with the tech between shops.

The certification also decides who can buy refrigerant.

Only EPA-certified technicians may buy ozone-depleting or substitute refrigerants such as HFCs, with limited exceptions, and your company may buy only by giving the wholesaler written evidence that it employs at least one certified technician.

Two edge cases keep the cards straight: servicing a vehicle's air conditioning is Clean Air Act Section 609 territory, not 608, and a 609-certified technician cannot buy refrigerant intended for stationary equipment regardless of container size.

Beyond refrigerant, the individual-licence question is answered state by state — and in Georgia and Michigan, the state's own licence paper sits at the company level.

Georgia has no state licence for individual HVAC technicians; it licenses conditioned air contractors (Class I and Class II) through the State Construction Industry Licensing Board.

Michigan licenses mechanical work only at the Mechanical Contractor level and issues no journeyman or technician licence for HVAC workers.

So before you write "must hold a state HVAC licence" into an ad, ask your state board which licence, if any, covers the technician level — the licence ladder on the tech's side is walked rung by rung in our HVAC technician licence guide.

Two scope notes close out the baseline.

The industry cards are never licences on their own — NATE, HVAC Excellence, NCCER and ASSE credentials are voluntary industry credentials, not government licences, though a state or a water utility can make a specific one mandatory for particular work.

And controls work raises its own licensing questions where it meets electrical scope; our research has not mapped that overlap state by state, so put it to your state board directly.

Gas is the credential employers miss most, because in much of the country it rides inside the plumbing or mechanical licence — until it doesn't.

HVAC techs who work on gas-fired equipment need a separate state gas credential in New Hampshire (fuel gas fitter), Utah (Certified Natural Gas Technician), Vermont (gas installer), Maine (propane & natural gas technician) and Massachusetts (gas fitter), and in New York City gas piping is plumbing work performed under a Master Plumber with a DOB Gas Work Qualification.

Widen the lens and the pattern is a map of its own: standalone state gas-fitter credentials, separate from the plumber licence, exist in Alabama, Alaska, Arkansas, the District of Columbia, Louisiana, Maine, Maryland, Massachusetts, New Hampshire, New Mexico, North Carolina, Utah, Vermont and Virginia.

Propane is its own layer in part of that map — separate LP-gas credentials or regulators were found in Texas (Railroad Commission), Arkansas, Alabama, Maryland, Massachusetts, Vermont, Maine and Virginia.

Texas shows how far the split can go.

LP-gas work there is regulated by the Railroad Commission, not TDLR or the plumbing board: each individual must pass an RRC exam for the activity they perform and must work for an RRC-licensed company.

Master or journeyman plumbers and Class A or B ACR contractors can instead register with the RRC for an LP-gas exemption covering LP-gas piping, containers and certain appliances, at $20 a year to renew.

Backflow testing switches on the same way, state by state.

Texas requires a TCEQ Backflow Prevention Assembly Tester (BPAT) licence for anyone who tests or repairs backflow prevention assemblies, and state-issued tester credentials also exist in Arkansas, Virginia, Wisconsin, Minnesota (where the tester needs ASSE 5110) and Washington (whose PL30 plumber specialty requires a DOH Backflow Assembly Tester certificate); Louisiana and Texas also offer licensed plumbers a "Water Supply Protection Specialist" endorsement.

Where the state issues no credential of its own, the ASSE Series 5000 standards name the roles: 5110 Backflow Prevention Assembly Tester, 5120 Cross-Connection Control Surveyor/Specialist, 5130 Backflow Prevention Assembly Repairer and 5150 Backflow Prevention Program Administrator.

Two renewal notes before you staff this work.

ASSE certifications must be renewed every three years, and for backflow testers in particular the water utility or the state often sets its own renewal cycle — commonly annual or biennial.

Medical gas is the third credential: the ASSE Series 6000 standards, whose 2024 edition parallels NFPA 99-2024, cover 6005 generalist, 6010 installer, 6020 inspector, 6030 verifier and 6040 maintenance, among other roles.

If you're staffing hospital or clinic work, ask which qualification the project documents name before the crew rolls.

Every rule in this section belongs to a named authority — a state fuel or plumbing board, the Railroad Commission, TCEQ, a state health department or a water utility.

Rules change, so confirm the current credential requirements with the board or utility that issues them before you dispatch an uncarded tech.

When candidates come in, each of these cards can be checked at its source: our verification guide shows where to verify a plumbing license, an EPA 608 card and a backflow credential before the start date.

The contractor licence and the individual licence answer two different questions, and mixing them up is the most common mapping error in a hire.

The contractor licence is the business's paper — the licence your company holds for the trade, issued by the state where the state licenses contractors at all.

The individual licence is the person's: what this specific employee may lawfully do on the truck.

Georgia and Michigan show the pattern where the state's paper is the company's alone.

Georgia licenses conditioned air contractors and has no state licence for individual HVAC technicians; Michigan licenses mechanical work only at the Mechanical Contractor level.

Staffing in a state like that, the credential question for each hire is answered by your company's licence plus whatever federal or specialty cards the task requires — there is no tech-level state card to chase.

The two papers also interlock in specific ways worth knowing.

Your company can buy refrigerant only by showing it employs a certified technician, so the company's purchasing legally rides on one individual's card.

Texas LP-gas certification requires the individual to work for an RRC-licensed company — the company licence and the individual credential each fail without the other — and a Texas BPAT may work on fire lines only while permanently employed by an Approved Fireline Contractor.

Which states license contractors statewide, what the licensed-person arrangement is called, and what happens when that person leaves are their own deep dives: our guides cover the HVAC contractor license and the plumbing contractor license state by state, and the HVAC contractor license qualifier — the licensed individual your company licence rides on.

Partly — and only where the rule that governs the task says so.

The clearest federal example is EPA 608: apprentices are exempt from certification only while they are closely and continually supervised by a certified technician, and the supervising technician and the apprentice share responsibility for compliance.

The rule sets no time limit on the exemption, so it can cover a helper's whole ramp-up — but "closely and continually" is the operative phrase, and it is the certified tech's compliance on the line, not just the helper's.

The buying rule does not stretch the same way.

Your company can buy refrigerant by showing it employs one certified technician, but that purchasing allowance does not certify the crew — anyone who opens a circuit without the supervision the exemption requires is outside the rules.

Gas work breaks the "one card covers the crew" assumption entirely.

A Texas RRC LP-gas exemption covers only the named individual — the holder's employees cannot work under it — and each individual must pass the RRC exam for the activity they perform.

Treat that as the default mental model for specialty credentials everywhere: a card belongs to a person, not to a truck.

Where you staff registered apprentices, the state's supervision ratios cap the arrangement on top of the federal rule — our apprentice supervision ratios guide collects them by state.

And once the mapping is done — task, credential, issuer — the rest of the process sits in our guide to hiring HVAC and plumbing techs.

This page is employer career and business information, not legal advice. Licensing and certification rules are set by state boards, cities, EPA and the certifying organizations — confirm the current requirements with the issuer for your state before you hire or dispatch.