How to check an engineer is Gas Safe registered

Gas work in the UK must be done by a Gas Safe registered engineer. That includes servicing a boiler, doing a landlord gas safety check, and repairing anything on the gas side. Checking registration takes a couple of minutes and is worth doing every time.

What Gas Safe registration means

The Gas Safe Register is the official list of businesses and engineers legally allowed to do gas work in Great Britain, Northern Ireland, the Isle of Man and Guernsey. It replaced CORGI in 2009, which is why landlord records are still sometimes called CP12, an old CORGI form name.

Each registered business has a registration number. Each engineer who works for it has their own licence number and ID card.

Step one: ask for the ID card

When the engineer arrives, ask to see their Gas Safe ID card. A genuine engineer expects this. The front of the card shows:

• The engineer’s photo
• Their name
• Their licence number
• The business they work for
• The card’s start and expiry dates

Check the photo matches the person and the card is in date.

Step two: turn it over

The back of the card is the part most people miss. It lists the kinds of gas work the engineer is qualified to do. Gas Safe engineers are qualified in categories, such as:

Category on card	Examples
Domestic boilers	Gas boilers in homes
Gas cookers and hobs	Cooking appliances
Gas fires	Fires and wall heaters
Meters	Gas meter work
LPG	Bottled or bulk liquid gas

If you have booked a boiler service, the card should show the engineer can work on domestic gas boilers. If you are a landlord booking a gas safety check that covers a boiler, a hob and a fire, the card should show all three.

Step three: check the number

You can check an engineer or business on the Gas Safe Register website. Enter the licence number from the card or the business registration number. The result shows whether they are registered and what they can work on.

You can do this when you book, using the business number, and again when the engineer arrives, using their card.

What to do if something does not match

If the card is out of date, the photo does not match, or the work you booked is not on the back, do not let the work go ahead. Explain politely and contact the company. You can report concerns to the Gas Safe Register.

Unregistered gas work is dangerous. A badly fitted or serviced boiler can leak gas or carbon monoxide.

Checking before you book

You do not need to wait until the day. When you book, ask for the business’s Gas Safe registration number and check it online. Ask whether the engineer coming is qualified for your type of boiler and any other appliances.

Landlords and lettings agents booking checks for several properties can save the business number and check it once a year.

After the visit

Your service record or gas safety record should include the engineer’s name and Gas Safe licence number. Check it is there. If you need to make a warranty claim, the boiler maker may want to see that a registered engineer did the service. Worcester Bosch, for example, says gas boilers must be serviced by a Gas Safe registered engineer to keep the guarantee valid. Our boilers we service page lists each maker’s wording.

Not everything is gas work

Some jobs on a heating system are not gas work and do not need a Gas Safe engineer:

• Bleeding radiators
• Topping up system pressure using the filling loop, if your manual shows how
• Thawing a frozen condensate pipe from outside

Anything that involves opening the boiler case, the gas valve, the burner or the flue is gas work. If in doubt, leave it to the engineer.

Communal heating

If you live in a newer block in places like central Croydon, your flat may not have a gas boiler at all. Some blocks run a communal heat network, with a heat interface unit in each flat. That is not gas work inside your flat, and it is serviced through the building’s heat supplier. If you are not sure what you have, check your lease or ask your managing agent. Our Croydon area page covers the town centre conversions and towers.

If you smell gas

If you smell gas at any point, call the National Gas Emergency Service on 0800 111 999. Turn off the gas at the meter if you can safely, open windows, and do not use switches or naked flames.

Quick checklist

• Ask for the business Gas Safe number when booking
• Check it on the register
• On the day, ask to see the engineer’s card
• Check photo, name and expiry date
• Turn the card over and check the work categories
• Make sure the licence number is on your record afterwards

When you book an annual boiler service, you can check the engineer’s card the same way. Our post on what a boiler service includes explains what the engineer should do once they start.