By Boiler Quotes Editorial Team · Updated 20 July 2026
What the Gas Safe Register Is
The Gas Safe Register is the official list of businesses and engineers legally permitted to carry out gas work in Great Britain, the Isle of Man and Guernsey. It replaced the CORGI scheme in 2009. Working on gas appliances without being registered is against the law, not merely bad practice.
Registration is not a general endorsement of quality. It confirms that the engineer has been assessed as competent for specific types of gas work. That last point matters, because competence is granted per category.
How to Check an Engineer, Properly
Every registered engineer carries a Gas Safe ID card. Checking it takes moments and is entirely reasonable to ask for.
- Ask to see the card before work starts. A genuine engineer will expect this and will not be offended.
- Check the front: photograph, name, licence number and the card's expiry date. An expired card is not valid.
- Check the back. This is the part most people skip and the most important. The reverse lists the categories of work the engineer is qualified for. Someone qualified on cookers is not automatically qualified on boilers.
- Verify the licence number on the official Gas Safe Register website, or by calling the register directly. You can search by business name or by the licence number on the card.
If anyone cannot produce a card, produces one in a different name, or becomes defensive when asked, do not let them touch your gas appliances.
What You Should Receive After the Work
Proper paperwork protects you when you sell the property, when you claim under warranty and if there is ever a dispute. After a boiler installation you should end up with:
- A Building Regulations compliance certificate. Your installer notifies Building Control of the installation, and you receive a certificate confirming it. This normally arrives within a few weeks.
- The completed Benchmark checklist in the boiler manual, filled in and signed at commissioning. Many manufacturers treat this as part of the warranty conditions.
- Manufacturer warranty registration confirmation.
- The appliance manual and any control instructions.
Keep all of it together. When you come to sell, buyers' solicitors routinely ask for the compliance certificate for a boiler installed since 2005.
Landlords Have Extra Duties
If you let a property, a Gas Safe registered engineer must carry out a gas safety check on the appliances and flues every twelve months, and you must give the tenant a copy of the record. This is a legal obligation with real consequences for non-compliance, and it is separate from servicing the boiler.
Carbon Monoxide: The Reason Any of This Matters
Badly fitted or poorly maintained gas appliances can produce carbon monoxide, which has no colour, taste or smell. Symptoms are easily mistaken for flu: headaches, dizziness, nausea and tiredness that improves when you leave the house.
Practical precautions:
- Fit an audible carbon monoxide alarm to the current British Standard in any room with a gas appliance, and test it regularly.
- Watch for warning signs on the appliance: a yellow or orange flame instead of crisp blue, sooty marks or staining around the boiler, excessive condensation in the room, or a pilot light that keeps going out.
- If you suspect carbon monoxide or smell gas, stop using the appliance, open windows, leave the property and call the National Gas Emergency Service on 0800 111 999.
Questions Worth Asking Before Booking
- What is your Gas Safe registration number?
- Are you qualified for this specific type of work, and can I see the back of your card?
- Who notifies Building Control, and when will I receive the certificate?
- Will you complete and sign the Benchmark checklist?
- Will you register the manufacturer's warranty on my behalf?
- What guarantee do you offer on your own workmanship, and for how long?
Every installer we match you with is Gas Safe registered, and you can verify any of them yourself before booking. Compare free, no-obligation quotes from up to 3 installers using the form below.
