Safety, certificates and compliance, 29 October 2026
F-gas certification for air conditioning installers
Yes. To install split air conditioning in Great Britain you need a personal F-gas qualification (Category 1, or Category 2 for systems under 3 kg of refrigerant) and your business needs an F-gas company certificate, even as a sole trader. Company certificates come from Refcom, the F-Gas Register (Quidos) or Bureau Veritas, and last three years.
Which F-gas qualification do you need?
The personal qualification depends on what you'll do and how much refrigerant the systems hold. GOV.UK sets out four categories for stationary refrigeration, air conditioning and heat pump work:
| Category | What it lets you do |
|---|---|
| 1 | All activities, any size of system |
| 2 | Install, maintain, service and recover refrigerant on systems under 3 kg, or under 6 kg if hermetically sealed |
| 3 | Recover refrigerant from systems under 3 kg, or under 6 kg if hermetically sealed |
| 4 | Check for leaks, without breaking into the refrigerant circuit |
If every system you fit holds under 3 kg, Category 2 covers you; anything larger needs Category 1. Check the nameplate charge plus any extra refrigerant for long pipe runs, because it's the system total that counts. You need your own qualification even if you work for someone else.
You need a Category 1 personal qualification, and your business needs a company certificate whose scope covers the system sizes you work on.
You need at least Category 2 for systems under 3 kg. Your business also needs a company certificate; Refcom requires engineers with Category 1 or 2 for that.
Category 3 covers recovery only. It doesn't count towards a company certificate, so it won't let your business install.
Category 4 covers leak checks that don't break into the circuit. It doesn't count towards a company certificate.
Wiring the supply to a unit isn't refrigerant work. Joining equipment or pipework to complete the refrigerant circuit is installation, and needs a qualified engineer and a certified company.
Does your business need a company certificate?
Yes, if you install, repair, maintain or decommission equipment that someone else operates. GOV.UK says companies, including sole traders, must hold certification from an approved body to do this. A business that only services its own equipment doesn't need one.
To qualify, you must show you employ enough qualified engineers and have written procedures for handling F gas safely. Refcom's FAQ says it needs a list of engineers holding City and Guilds 2079 Category 1 or 2 or equivalent, and proof of recovery equipment and refrigerant handling procedures. Category 3 or 4 alone isn't enough. Subcontractors need their own certificate; you can't cover them under yours.
What does company certification cost?
Refcom lists its fees by firm size, each covering a three-year certificate and subject to VAT. That makes it a small cost next to the work it opens up.
Refcom company certificate, cost per year
Refcom fees as listed on its FAQ page, October 2026.
| Sole trader (micro)£143 + 20% VAT | £171.60 |
| Per year over three years£171.60 ÷ 3 | £57.20 |
| Two to nine engineers (small)£184 + 20% VAT | £220.80 |
| Per year over three years, small firm£220.80 ÷ 3 | £73.60 |
Medium firms of 10 to 49 engineers pay £372, and large firms £680. The F-Gas Register (Quidos) and Bureau Veritas also certify; compare their terms if you prefer.
Can an electrician or plumber fit air con without F gas?
Not the refrigerant side. An electrician can wire the supply and isolator to an air conditioning unit without an F-gas qualification, because that isn't work on the refrigerant circuit. Installation in F-gas terms includes joining equipment or refrigerant pipework to complete a refrigerant circuit, and that needs a qualified engineer working for a certified business.
There are two narrow exemptions. Someone who only brazes, solders or welds on the system can do so without an F-gas qualification if they hold a recognised qualification for that work and are supervised by a certified engineer. Trainees enrolled on an F-gas course can work under supervision for up to 24 months in total.
"Pre-charged" split units don't get round this. The law says non-hermetically sealed equipment charged with F gas may be sold to an end user only where there's evidence a certified business will install it, and GOV.UK tells sellers to ask for the installer's details in writing. Suppliers must also sell refrigerant only to certified businesses.
What's the paperwork once you're certified?
Leak checks, records and labels. Systems at or above 5 tonnes CO2 equivalent need leak checks at set intervals, and you must keep records of the refrigerant you add and recover. Refcom says to keep records for five years. Our guide to F-gas record keeping and leak checks covers the intervals and what to log.
Firms that add air con to a heating business often find the paperwork lands at once: quotes, F-gas records, RAMS for each site and, sometimes, planning questions from the customer.
I've got 22 aircon quotes to do this weekend… I'll be here all weekend.
For the questions customers ask next, see air conditioning and planning permission and site-specific RAMS from a master template.
Does Northern Ireland follow the same rules?
Not exactly. The F-gas rules were kept in UK law after Brexit, but Northern Ireland and Great Britain now have different legislative arrangements, and the GOV.UK guidance above applies to Great Britain. If you work in Northern Ireland, check the current position with your certification body before you quote. Scotland and Wales follow the Great Britain rules.
Where Nexley fits
Nexley is the AI back office for UK trade firms: five AI assistants run your tenders, quotes, buying, scheduling and invoicing. It connects to the tools you already work in, you run it all from WhatsApp, and you approve everything. £799 a month.
Nexley keeps the paperwork that comes with air con work moving. Send a site photo and a voice note on WhatsApp and it drafts the quote from your price list, the RAMS from your master and the F-gas record for the system, for you to check and approve. It reminds you when leak checks are due and when your company certificate needs renewing.
Common questions
Do I need F-gas to install air conditioning?
Yes, for the refrigerant work. Connecting the refrigerant circuit, evacuating and charging the system all need a personal F-gas qualification (Category 1, or Category 2 under 3 kg), and your business needs a company certificate.
Do sole traders need an F-gas company certificate?
Yes. GOV.UK and Refcom both say sole traders who install or service other people's equipment need a company certificate as well as their personal qualification.
How long does an F-gas company certificate last?
Three years. Refcom says certificates must be renewed on or before expiry, and it contacts you before the due date.
Can I buy a pre-charged air con unit and fit it myself?
The supplier must not sell non-hermetically sealed equipment to an end user without evidence that a certified business will install it. Connecting it is installation under the F-gas rules, so it needs a qualified engineer and a certified company.
Sources
- GOV.UK: Qualifications to work with F gas
- GOV.UK: Company certification to work with F gas
- Refcom: F-gas FAQs and fees
- GOV.UK: Selling F gas in cylinders or equipment
- legislation.gov.uk: Regulation (EU) No 517/2014, Article 11
- legislation.gov.uk: Regulation (EU) 2015/2067 (certification of persons and companies)
- GOV.UK: Bans on F gas in new products and equipment
- GOV.UK: F gas guidance, September 2024
Every rule, rate and date above was checked against these sources on the date shown at the top.
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