Gas Safe Registration: What Work Requires It, Penalties & How to Verify
Quick Answer: All work on gas fittings, appliances, and pipework in the UK (except the act of bleeding a radiator or replacing a tap washer on a gas tap) must be carried out by a Gas Safe registered engineer. Gas Safe replaced CORGI in April 2009. The legal requirement comes from the Gas Safety (Installation and Use) Regulations 1998 (GSIUR). Operating as an unregistered engineer carries an unlimited fine and/or up to 6 months imprisonment.
Summary
Gas Safe registration is a legal requirement, not an industry accreditation. It is the scheme approved by the Health and Safety Executive (HSE) under the Gas Safety (Installation and Use) Regulations 1998 to ensure that anyone working on gas is competent to do so safely. Unlike CORGI (which preceded it until April 2009), Gas Safe is mandatory under statute — an engineer must hold a valid Gas Safe card for the specific type of gas work they are undertaking.
The most important concept for tradespeople to understand is that Gas Safe registration is not a blanket "I can do all gas work" licence. The card specifies the categories and gas types the engineer is registered for. A Gas Safe engineer registered for domestic natural gas (NG) boilers is not automatically registered to work on LPG, commercial catering equipment, or industrial gas plant. Working outside your registered categories is just as illegal as working unregistered.
For clients, including landlords and letting agents, understanding Gas Safe is increasingly important. Landlords have a statutory obligation to have an annual Gas Safety Check carried out by a registered engineer and to provide tenants with a copy of the certificate. Failure to do so is a criminal offence. The Gas Safe Register is a public database — anyone can verify an engineer's registration and categories online at no cost.
Key Facts
- Gas Safe Register — the UK's official gas registration body; replaced CORGI in April 2009; operates in Great Britain, Northern Ireland (with NIGas), Isle of Man, and Guernsey
- GSIUR 1998 — Gas Safety (Installation and Use) Regulations 1998; the primary legislation; Regulation 3: only a registered person or their employer may work on gas fittings
- Penalty for unregistered work — unlimited fine and/or 6 months imprisonment under the Health and Safety at Work etc. Act 1974 and GSIUR 1998
- Gas Safe card — must be carried at all times during gas work; shows name, photo, registration number, gas types (NG/LPG) and appliance categories (e.g., CCN1, CPA1, WAT1)
- CCN1 — the core domestic natural gas competency; covers installation of gas pipework and tightness testing; required for most domestic gas work
- CPA1 — central heating appliances (boilers and heat pumps); required for boiler installation
- WAT1 — gas warm air heaters
- MET1 — gas meters (only energy supplier/DNO engineers may work on gas meters)
- Annual Gas Safety Check — required for all rented properties (Regulation 36, GSIUR); must be carried out by Gas Safe registered engineer; must be recorded on a CP12 form; copy given to existing tenant within 28 days; new tenant given copy before or at start of tenancy
- CP12 — the Landlord Gas Safety Record; common name for the certificate issued after an annual gas safety inspection
- RIDDOR — Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013; gas incidents (e.g., CO poisoning) are RIDDOR reportable
- Immediately Dangerous (ID) — a gas appliance or installation assessed as posing an immediate risk to life; engineer must disconnect/isolate before leaving site and label accordingly
- At Risk (AR) — a gas situation that is not immediately dangerous but could become so; must be reported to occupant and noted; owner should be advised to remedy
- Not to current standards (NCS) — a gas installation that doesn't meet current standards but is not currently at risk; must be noted and owner advised
Quick Reference Table
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Try squote free →| Work Type | Gas Safe Registration Required? |
|---|---|
| Installing or replacing a gas boiler | Yes — CCN1 + CPA1 minimum |
| Connecting a gas cooker (rigid or bayonet) | Yes — CCN1 |
| Installing gas pipework | Yes — CCN1 |
| Tightness testing | Yes — CCN1 |
| Servicing a gas appliance | Yes — appropriate appliance category |
| Annual landlord safety check | Yes — appropriate appliance categories |
| Replacing a gas fire | Yes — CCN1 + fire category |
| Fitting a gas meter | No (energy supplier only) |
| Bleeding a radiator | No |
| Replacing a tap washer on a gas tap | No — but extreme caution required |
| Moving a gas meter | No (energy supplier only, apply via National Grid/Cadent) |
| Connecting a gas hob (flexible hose to bayonet) | Yes — CCN1 |
Detailed Guidance
How Gas Safe Registration Works
To become Gas Safe registered, an engineer must:
- Hold a current ACS (Assessed Competence Scheme) certificate for each gas appliance category they wish to work on. ACS assessments are run by approved UKAS accredited centres (City & Guilds NICEIC, Capita, etc.)
- Apply to Gas Safe Register with evidence of current ACS certificates
- Pay an annual registration fee
- Receive a Gas Safe card for each registration category
ACS certificates last 5 years for most categories. Engineers must re-sit assessments before their certificates expire to maintain registration.
The Gas Safe card categories are central to compliance:
- The card shows each ACS category the engineer holds
- The card has an expiry date
- Always check the specific category on the card before starting work — "Gas Safe registered" doesn't mean registered for all work
Verifying Gas Safe Registration
Anyone can check a Gas Safe registration:
- Online: gassaferegister.co.uk — search by registration number, name, or postcode
- Phone: 0800 408 5500
- QR code: on the Gas Safe card, a QR code links to the engineer's registration details
Homeowners and landlords should always verify registration before allowing gas work to proceed. This is not insulting — it's legally prudent. An unregistered engineer's work is unlawful and any gas appliance work done by an unregistered person should be re-inspected by a registered engineer.
Unsafe Situations: ID, AR, NCS
When a Gas Safe engineer inspects gas appliances, they classify any deficiencies using a three-tier system defined in the IGEM/G/SR1 Gas Industry Unsafe Situations Procedure:
Immediately Dangerous (ID): the appliance or installation presents an immediate risk of injury, death, or gas escape. Action: the engineer MUST isolate the supply and attach a "Do Not Use" label (using Gas Safe labelling system). The engineer cannot legally leave the appliance operational. If the owner refuses isolation, the engineer must inform Gas Safe Register and the gas transporter.
At Risk (AR): the appliance or installation is operating outside safe limits but is not immediately dangerous. The appliance may continue to operate but the owner must be clearly warned and given written notice. If a tenant is involved, the landlord must be informed.
Not to Current Standards (NCS): the installation doesn't meet current standards but is not dangerous. No immediate action required — owner advised to upgrade at next opportunity. This is the most common classification for old-but-working appliances that predate current standards.
Landlord Obligations
Under Regulation 36 of GSIUR 1998, landlords must:
- Arrange an annual gas safety check on every gas appliance and flue in every rented property
- Have the check carried out by a Gas Safe registered engineer
- Keep records of the check for 2 years
- Provide the current CP12 to existing tenants within 28 days of the check
- Provide the CP12 to new tenants before or at the start of their tenancy
Recent update: since April 2018, landlords in England may carry out the annual gas safety check anytime within 2 months before the due date without losing the original anniversary date for future checks.
Failure to comply with Regulation 36 is a criminal offence under GSIUR 1998. Penalties are unlimited fine and/or 6 months imprisonment. HSE enforcement is active — multiple prosecutions occur each year.
Gas Work Notifications
Unlike electrical work (which has Competent Person self-certification schemes), there is no self-certification scheme for gas work — all notifiable gas work is inherently self-certified by the Gas Safe registration system. The Gas Safe Register receives notification of work completed automatically from registered engineers via their registration documentation.
For boiler installations and certain other work, the engineer must notify the Gas Safe Register. Some work also requires Building Regulations notification (e.g., new boiler installation in England and Wales must be notified to building control, which can be done via Gas Safe's linked notification service).
Frequently Asked Questions
Can a plumber do gas work if they hold a Gas Safe card?
Yes — many plumbers hold Gas Safe registration. "Gas Safe registered" is the qualification; being a plumber or heating engineer is the trade. The key is that the individual (not the company) holds the appropriate ACS assessments and current Gas Safe card categories.
What should I do if I discover an unregistered gas engineer has done work?
Advise the client to have all the gas work re-inspected by a Gas Safe registered engineer immediately. Do not operate any gas appliances that may have been installed or connected by an unregistered person until they have been inspected. Report concerns to the Gas Safe Register (0800 408 5500) and/or the HSE.
Can a Gas Safe engineer refuse to work on an appliance?
Yes. A Gas Safe engineer is legally empowered — and obligated — to take unsafe appliances out of service. If an engineer declares an appliance ID and issues a "Do Not Use" label, the owner has no legal right to continue using it until it is rectified by a competent person. Operating a gas appliance after an ID classification is a criminal offence.
I'm a builder fitting a kitchen — can I move the gas pipe 50mm to fit a cabinet?
No — any work on a gas fitting, including moving pipework by any distance, requires Gas Safe registration. Even disconnecting and reconnecting a bayonet fitting requires Gas Safe registration. Subcontract all gas pipework moves to a Gas Safe registered engineer.
Regulations & Standards
Gas Safety (Installation and Use) Regulations 1998 (GSIUR 1998) — the primary legislation for all gas work in premises; Regulation 3 (registration), Regulation 36 (landlord obligations)
Health and Safety at Work etc. Act 1974 — overarching health and safety legislation under which gas safety offences are prosecuted
Gas Act 1986 — establishes the framework for gas supply and transport; defines the gas transporter's responsibilities
IGEM/G/SR1 — Gas Industry Unsafe Situations Procedure; defines ID, AR, and NCS classifications
IGEM/UP/1B — purging, commissioning, and decommissioning of gas appliances
IGEM/UP/2 — installation pipework on industrial and commercial premises
Gas Safe Register — verify engineers, find registered engineers, report concerns
HSE — Gas Safety — regulatory guidance and enforcement
GOV.UK — Landlord Gas Safety — landlord obligations summary
IGEM — Technical Standards — industry guidance notes
boiler installation — boiler installation requirements and benchmarking
carbon monoxide — CO alarm requirements and landlord obligations
gas pipe sizing — domestic gas pipe sizing calculations
lpg installations — LPG-specific registration and safety requirements
competent person — competent person schemes overview