How do I check a gas engineer is Gas Safe registered?

Why registration matters

Regulation 3 of the Gas Safety (Installation and Use) Regulations 1998 says nobody may carry out work on a gas fitting unless they are competent, and that businesses doing gas work must be members of a class of persons approved by HSE. In practice that means the Gas Safe Register. HSE's guidance for employers puts it simply: in homes and in workplaces such as shops, restaurants, schools and hospitals, gas work must be done by a Gas Safe registered engineer who is qualified for that work, and it is illegal for anyone else to do it.

Gas Safe Register is a list of businesses. Each registered business has a registration number, and each engineer working for it carries their own Gas Safe ID card with a personal licence number.

What to check on the front of the ID card

• The photo: it should be the person standing at your door.
• The licence number: a seven-digit number you can check online. A new card is issued every year and the licence number changes when it is.
• The business name and registration number: these should match the company you booked.
• The valid from and expiry dates.

Why the back of the card matters more

Gas Safe Register's own advice is to read the back of the card even when the front looks right, because not every engineer can work on every type of appliance. The back lists the engineer's qualifications, split into domestic and non-domestic work, each with its own expiry date. If the engineer has come to service your boiler, for example, the card should list "Gas Boiler". The minimum qualification is pipework, and engineers add appliance categories on top of that.

The card also shows whether the engineer is qualified for natural gas, LPG or both. If your boiler runs on LPG, or the work is in a business, check that the right column and category are covered. Our guide to domestic and commercial gas engineers explains the difference.

How to check an engineer or business online

1. Go to the Gas Safe Register website and use the check an engineer service with the licence number from the card. You will see the engineer's photo and current qualifications.
2. To check a business, search by its trading name or Gas Safe registration number.
3. To find an engineer, search by postcode, choose domestic or commercial, then the appliance type.
4. If you cannot get online, call Gas Safe Register on 0800 408 5500.

Other sensible checks before you book

• Ask for the price basis in writing: what the visit covers, whether VAT is included, and what depends on a site inspection.
• Ask who will attend, and whether they hold the categories for your appliance.
• Read recent reviews and check the company's details on Companies House if it is a limited company.
• Expect a record after the work. Landlords must receive a gas safety record after a safety check; see our landlord CP12 guide.

What to do if someone will not show a card

Gas Safe Register says that if an engineer cannot show a valid ID card, or refuses to, you should not let them carry out the work. If you think someone is doing gas work illegally, you can report them to Gas Safe Register online or on 0800 408 5500. Note names, dates and the address where the work was done.

Checking CombiCert

CombiCert Ltd's Gas Safe business registration number is 621146. You can check it on the Gas Safe Register before you book, and ask our engineer to show their ID card when they arrive. Our company details, including Companies House number 12155826, are on Peter Jefferson's author page.

This guide is general information, not a substitute for an on-site assessment by a Gas Safe registered engineer. If you smell gas, call 0800 111 999.