How to Check If a Plumber Is Gas Safe Registered

It is illegal in the UK for anyone who isn't on the Gas Safe Register to carry out work on a gas appliance — boilers, gas hobs, gas fires, gas water heaters, or any pipework connected to them. The penalty for getting it wrong isn't just a regulatory issue — unregistered work has caused fatalities every year that the Health and Safety Executive tracks. Verifying takes 30 seconds and should be done every time, no matter how trusted the contractor.

The five-step check before any work begins

1. Ask to see the engineer's Gas Safe ID card. Every registered engineer carries one and is required to present it on request. There is no acceptable excuse for not having one.
2. Check the photo matches. The card shows a photograph of the registered engineer. Confirm the person standing in front of you is the person on the card.
3. Check the expiry date. Cards are reissued annually. An expired card means an out-of-date registration.
4. Check the appliance categories on the back. Gas Safe registration is granted by appliance type. A boiler engineer is not automatically qualified to work on gas fires, range cookers, or commercial catering. The card lists each category the engineer is registered for.
5. Verify the seven-digit licence number online. Go to gassaferegister.co.uk, use the "Check the Register" tool, and enter the number. The result confirms the engineer is current, identifies the registered business, and shows the qualified work scopes.

What can go wrong with unregistered work

Three failure modes catch homeowners out:

• Carbon monoxide leaks. Incorrectly installed flues, poorly adjusted burners, and missing ventilation can all release CO into the property. CO is colourless and odourless. Domestic CO incidents kill an average of 30 people a year in the UK and hospitalise hundreds more.
• Gas leaks. Improperly sealed joints can release natural gas into the home, creating an explosion risk. Insurance won't cover damage from unregistered work, even if the cause was clearly the contractor's fault.
• Voided warranty. Boiler manufacturer warranties require all servicing and repair work to be carried out by Gas Safe registered engineers. A single unregistered visit can void the warranty permanently.

Common warning signs

If someone offering gas work shows any of these patterns, walk away:

• Refusing or making excuses about presenting the ID card
• "I left my card at the office — I'll bring it next time"
• Discounting heavily for cash payment with no paperwork
• Doing the work without first taking down meter readings or testing existing installations
• Showing a card from a different person ("I work for them")
• An ID card from another country or a different trade body (CORGI ceased to be the registration body in 2009)

CORGI registration is no longer valid in the UK. Anyone showing a CORGI card as proof of qualification is either out of date or attempting to deceive you. The only legitimate register is Gas Safe.

How to find a registered engineer

The Gas Safe Register's free "Find an Engineer" search lets you look up registered businesses by postcode, town, or specific qualification. Each result shows the registered company name, the engineers attached to it, and the scope of work they're qualified for. You can also call the Gas Safe Register on 0800 408 5500 for the same information by phone.

When booking gas work in Peterborough, we always present our Gas Safe ID at the start of the visit. Our registration covers domestic natural gas boilers, gas fires, gas cookers, and meter work — full detail is on our gas safety certificate page, and you can verify our registration directly with the Gas Safe Register before booking.

What to do if you've already had unregistered work done

If you suspect a previous installation or repair was carried out by someone unregistered:

1. Stop using the affected appliance immediately
2. Book a Gas Safe registered engineer to inspect the work and confirm it's safe
3. Get a written report — useful if you later need to claim against the contractor or insurance
4. Report the unregistered contractor to the Gas Safe Register on 0800 408 5500 — they can prosecute

If the inspection reveals dangerous work, the engineer can issue an "Immediately Dangerous" notice and disconnect the appliance until safe. This sounds severe but it's the right outcome — every year, post-incident investigations identify dangerous installations that had been in place for months or years without warning signs.

Verifying takes less time than reading this paragraph. Make it a habit.