What does a Gas Safe certificate mean?

In the UK there is no single "Gas Safe Certificate". The phrase usually refers to one of three documents: the engineer's Gas Safe ID card (proves they are legally registered), a Gas Safety Record / CP12 (issued after a safety check, required annually for landlords) or a Building Regulations Compliance Certificate (issued after a notifiable install like a new boiler). All three rely on the engineer being a current member of the Gas Safe Register.

Is Gas Safe the same as CORGI?

No. CORGI was replaced by the Gas Safe Register on 1 April 2009. Any engineer still claiming to be "CORGI registered" is either out of date or not legally allowed to work on gas. The Gas Safe Register is the only body authorised by HSE to register gas engineers in Great Britain, the Isle of Man and Guernsey.

How long is a Gas Safe certificate valid?

It depends which document. A Gas Safety Record (CP12) is valid for 12 months and must be renewed annually for landlords. A Building Regulations Compliance Certificate confirms the install met the regulations on the day — it does not "expire" but the appliance still needs annual servicing to stay safe. The engineer's Gas Safe registration itself runs for one year and is renewed annually.

Do I legally need a gas safety check as a homeowner?

No — homeowners are not legally required to have an annual gas safety check. Landlords are, under the Gas Safety (Installation and Use) Regulations 1998. However, almost all boiler manufacturers require an annual service by a Gas Safe engineer to keep the warranty valid, and most home insurers expect evidence of regular servicing if you make a gas-related claim.

What is the difference between a gas safety record and a service?

A safety check confirms the appliance is safe to use right now — it tests for leaks, checks the flue, measures combustion and verifies ventilation. A service is more thorough — it includes the safety checks plus cleaning, replacing worn parts and checking controls. Some engineers combine them; others charge separately. For most homeowners a full service every 12 months covers both.

What does the back of a Gas Safe card show?

The back of the card lists the categories of gas work the engineer is qualified to do. Examples include "Central heating boilers natural gas", "Cookers LPG", "Unvented hot water", "Commercial catering" and many others. Each category has an expiry date. The card may also note any restrictions. If your job type is not listed, the engineer is not qualified for it, even if they hold other categories.

What should I do if I think a gas engineer is not properly registered?

Stop the work immediately if it has not started, do not pay in cash and contact Gas Safe Register on 0800 408 5500 to report them. If you are concerned about a recent install, ask Gas Safe to send a registered engineer for a free safety inspection. If you smell gas, call the National Gas Emergency line on 0800 111 999 first, then report the original installer separately.

What Does a Gas Safe Certificate Actually Mean?

There is no such thing as a single Gas Safe Certificate — but three different documents go by the name. Here is what each one proves, how to verify it, and the red flags that tell you to stop the work.

Find a Gas Safe Plumber

Four Things to Know First

A quick grounding before the document-by-document breakdown.

It is the engineer, not the certificate

There is no single "Gas Safe Certificate". What you check is the engineer's Gas Safe Register ID card. The paperwork you receive after a job is a Building Regulations Compliance Certificate or a Gas Safety Record — different documents, all backed by the engineer's registration.

Legally required for gas work

Since 2009 it has been illegal in the UK for anyone to carry out gas work in a home or business without being on the Gas Safe Register. This replaced the old CORGI scheme. Fines and prosecution are real — every year HSE prosecutes unregistered fitters after gas incidents.

Cards expire — check the date

Every Gas Safe card has an expiry date on the front. Engineers must renew their qualifications every five years and pay an annual subscription. If the card is out of date, the engineer is not legally registered, regardless of past experience.

The card lists what they can do

The back of the card lists the categories of gas work the engineer is qualified for — for example "Cookers natural gas", "Central heating boilers LPG", "Unvented hot water". Just because someone is Gas Safe registered does not mean they are qualified for every kind of gas job.

The Four Documents Homeowners See

When people say "Gas Safe certificate" they usually mean one of these. Each proves something different.

Gas Safe ID Card

When you get it: The engineer arrives

A photo card with the engineer's name, registration number, expiry date and qualification categories. Ask to see it before work starts.

Proves:That the engineer is legally allowed to work on gas in your home today.

Building Regulations Compliance Certificate

When you get it: After a notifiable install (new boiler, gas fire, cooker)

Issued by the engineer through Gas Safe Register within 30 days of the install. You also receive a Building Regulations notice from your local council.

Proves:That the install complies with Part J and Part L of the Building Regulations. Essential when you sell the property.

Gas Safety Record (CP12)

When you get it: After an annual gas safety check

A record of the appliances checked, the readings taken and any defects identified. Landlords must obtain one annually for every rental property by law.

Proves:That the appliances were tested as safe on the date of inspection. Required by landlord law; useful for homeowners too.

Boiler Service Record

When you get it: After an annual boiler service

A record of the service work — filter cleaned, flue checked, combustion analysis, controls tested. Often combined with the safety record.

Proves:That the manufacturer's warranty conditions have been met — most warranties require an annual service by a Gas Safe registered engineer.

How to Verify a Gas Safe Engineer

Four checks that take five minutes and save you from cowboys.

Look up the engineer at gassaferegister.co.uk

Go to the official Gas Safe Register search. You can search by name, business name, postcode or registration number. The result shows the engineer's photo, business details and the categories of gas work they are qualified for. This is the only authoritative check.

Match the card to the person on the doorstep

Ask to see the physical card. Check that the photo matches the engineer, that the expiry date has not passed and that the registration number on the card matches the one in the online register.

Check the category covers your job

The card lists categories like "Central heating boilers natural gas" or "Cookers LPG". Make sure your specific appliance type and fuel are covered. A natural gas boiler engineer is not automatically qualified for LPG, and vice versa.

Confirm the business is on the register too

Gas Safe registers the business as well as the individual. If the engineer works for a company, the business should also be on the register. This matters if you need to make a complaint or claim later.

Red Flags: Stop the Work

Any of these, and the engineer is either not registered or not legitimate. Walk away.

Refuses to show their Gas Safe card or claims to have left it in the van
Card photo does not match the person on your doorstep
Registration number does not appear when you search the official register
Card has expired or covers different categories than the job needs
Insists on cash only and refuses to provide a written quote or invoice
Says they are "CORGI registered" — CORGI has not existed since 2009
Cannot or will not register a new boiler install with Building Control

Report unregistered gas work to Gas Safe Register on 0800 408 5500. If you smell gas, call the National Gas Emergency line on 0800 111 999 first.

Gas Safe Certificate FAQs

Book a Verified Gas Safe Plumber in Exmouth

Every Gas Safe registered plumber in our verified directory has had their card and registration number checked. You can search the official register yourself before booking — we list the numbers on each profile.

Find a Gas Safe Plumber

For more on gas qualifications, see our Gas Safe plumber guide. Not sure whether you need a plumber or a heating engineer? Read plumber vs heating engineer. For boiler service intervals see how often to service your boiler. For new boiler pricing see new boiler cost. For wider pricing context see plumber costs.