In 10 seconds
By UK law (Gas Safety (Installation and Use) Regulations 1998), only Gas Safe registered engineers can legally work on natural gas or LPG installations in your home. Verify any engineer at gassaferegister.co.uk before they touch your boiler, hob, or pipework.
The law: who can work on gas in Wales
The Gas Safety (Installation and Use) Regulations 1998 (made under the Health and Safety at Work etc. Act 1974) make it a criminal offence for anyone to install, service, or repair gas appliances in a dwelling unless they are on the Gas Safe Register. Wales follows the same regulation โ the legislation is UK-wide and not devolved.
This covers boilers, gas hobs and ovens, gas fires, water heaters, and the pipework between the meter and any appliance. It applies whether you own or rent. Landlords have an additional legal duty (a yearly Landlord Gas Safety Record) that only a Gas Safe engineer can issue.
What "Gas Safe registered" actually means
Gas Safe Register is the official body that replaced CORGI in April 2009. Each engineer carries a photo ID card listing the specific categories of gas work they are individually qualified for โ being on the register is not a blanket licence.
When checking the back of a Gas Safe card, look for the categories relevant to your job:
- CCN1 โ Domestic gas safety (core competence; required for all domestic gas work).
- CENWAT โ Central heating boilers and water heaters.
- CKR1 โ Cookers.
- HTR1 โ Gas fires and wall heaters.
- MET1 โ Domestic gas meters.
- LPG categories (e.g. CONGLP1, CKLPG1) โ for liquid petroleum gas (separate from natural gas).
How to verify before any work starts
There are three legitimate ways to confirm a Gas Safe engineer is genuine, in increasing reliability:
- Ask to see their Gas Safe ID card (front and back). The front shows their name, photo, and a 7-digit licence number. The back lists what they are qualified to do, with an expiry date.
- Search the engineer's name, postcode, or licence number at gassaferegister.co.uk/find-an-engineer. The site returns a live record showing their categories and whether their registration is current.
- For business-level checks, look up the company's registration number. A genuine business will have a 6-digit business registration number alongside individual engineers' 7-digit numbers.
Welsh-specific notes
Welsh Government does not run a separate gas register โ the UK-wide Gas Safe Register applies. However, the Welsh Government enforces additional duties on private landlords through Rent Smart Wales: every landlord must hold a current Landlord Gas Safety Record (CP12) for each rented property, and Rent Smart Wales may request evidence as part of landlord registration. Tenants can report concerns to Rent Smart Wales directly.
The Health and Safety Executive (HSE) is the enforcement body across Wales and England for the 1998 regulations.
Penalties for non-compliance
A person carrying out gas work without registration commits a criminal offence under the 1998 regulations. Reported cases have resulted in unlimited fines under the magistrates' court process and, in serious or repeat cases, imprisonment of up to two years on indictment. The most recent HSE enforcement notices and prosecutions are listed publicly on hse.gov.uk/notices/.
For homeowners, the more common practical risk is a non-compliant installation that voids your home insurance and, on house sale, may require remediation before a buyer's survey clears.
Common scams to watch for in Wales
Three patterns reported by Gas Safe Register and Welsh Trading Standards:
- Cloned or expired cards โ the engineer shows a real-looking card but their registration has lapsed. Always check the live register, not just the card.
- Cold-callers offering "free boiler safety checks" โ Gas Safe engineers do not cold-call. Any unsolicited doorstep gas inspection should be refused and reported to Trading Standards.
- "Cash discount, no paperwork" โ a Gas Safe engineer is required by law to issue a Building Regulations compliance certificate within 30 days of replacing a boiler. Cash-no-paperwork is a strong signal the work is unregistered.
How to verify a Gas Safe engineer in Wales
- Ask for the card. Request the engineer's Gas Safe ID card and note the 7-digit licence number on the front.
- Check the back. Confirm the categories on the back of the card cover the work being done (e.g. CENWAT for a boiler).
- Verify the licence. Search the licence number at gassaferegister.co.uk/find-an-engineer to confirm the registration is current.
- Confirm the business. Cross-check the business name and 6-digit business registration number on the same site.
- Keep the certificate. After installation work (especially a boiler replacement), insist on the Building Regulations compliance certificate the engineer must issue within 30 days.
Frequently asked questions
Can I do my own gas work?
No. Even minor work on gas appliances in your own home is restricted by the 1998 regulations. The only exception is fully-self-contained appliances that simply plug into an existing gas point and have a manufacturer-fitted certified connection (rare in practice).
What's the difference between Gas Safe and CORGI?
CORGI was the previous register and was replaced by Gas Safe on 1 April 2009. Anyone still claiming to be "CORGI registered" today is not currently registered with the active scheme.
Do I need Gas Safe for an oil boiler?
No โ oil is not covered by Gas Safe. Oil-fired appliance work is covered by OFTEC (Oil Firing Technical Association). Their register is at oftec.org/find-a-technician.
How often does a gas boiler need a Gas Safe service?
Most manufacturers require an annual service by a Gas Safe engineer to maintain warranty. Landlords have a separate legal requirement to obtain an annual Landlord Gas Safety Record. Owner-occupiers have no annual legal duty but it is strongly recommended for safety and insurance.
What if my engineer's card is showing an expired date?
Stop the work. An expired ID card means the engineer's competence in those specific categories has not been re-certified. Verify the live status at gassaferegister.co.uk before proceeding.
Who do I report an unregistered gas worker to in Wales?
Report directly to Gas Safe Register via gassaferegister.co.uk/contact (online form) or 0800 408 5500. You can also report to your local Welsh Trading Standards via citizensadvice.org.uk.
Does Gas Safe registration cover LPG (bottled gas) appliances?
It can โ but the engineer needs the specific LPG categories on their card (e.g. CONGLP1 for natural gas/LPG conversions, CKLPG1 for LPG cookers). Many engineers only hold natural-gas categories. Always check the back of the card for the LPG category that matches your appliance.
My landlord won't show me the CP12 โ what now?
In Wales, landlords must hold a valid CP12 and provide a copy to any new tenant within 28 days of issue, and to existing tenants within 28 days of the annual renewal. If a landlord refuses, Rent Smart Wales can investigate โ contact them via gov.wales/rent-smart-wales.
Sources
- Gas Safety (Installation and Use) Regulations 1998 โ Primary UK law governing domestic gas work.
- Gas Safe Register โ find an engineer โ Live lookup of registered engineers by name, postcode, or licence number.
- HSE โ Gas Safety guidance โ Health and Safety Executive guidance on the 1998 regulations.
- Rent Smart Wales โ Welsh landlord registration body โ enforces CP12 requirements.
- OFTEC โ oil-firing technician register โ Equivalent register for oil-fired appliance work (not covered by Gas Safe).
Find a verified plumber in Wales