Reviewed by qualified compliance practitioners·Last updated 30 April 2026
Gas Safety — Plain English Guide
Straight answers about gas safety: what landlords must do, what a CP12 is, when commercial premises need inspections, and how to find a Gas Safe engineer. Written for landlords, business owners, and people in charge of buildings.
Looking for the technical detail? Read the version for professionals → GSIUR 1998, ACoP L56, commercial catering (IGEM/UP/19), and LPG installations.
What is gas safety?
Making sure gas appliances, pipework, and flues are safe so they don't leak, explode, or produce carbon monoxide.
Is a gas safety check a legal requirement?
Yes — for landlords. Every 12 months under the Gas Safety (Installation and Use) Regulations 1998.
For owner-occupied homes, there's no legal requirement to have an annual check, but it's strongly recommended.
For commercial premises, you must keep gas installations safe and serviced — annual safety checks are the standard way to do this.
What is a CP12?
A Gas Safety Record. The "CP12" name is industry shorthand from an older form number, but it's still widely used.
It's the certificate a Gas Safe engineer issues after the annual landlord gas safety check.
Do I need a gas safety check for my business?
Yes — if you have any gas appliances. Boilers, water heaters, commercial cookers, and ovens all need annual checks.
Who is responsible for gas safety?
You are. If you own or run the building, manage the property, or operate the gas appliances, it's your responsibility.
For rentals: it's the landlord, even if the tenant supplies their own appliances.
How often does a landlord need a gas safety check?
Every 12 months. The check must be carried out within 12 months of the last one.
When must I give the certificate to tenants?
Within 28 days of the check. New tenants should get a copy before they move in.
What happens if I don't have a gas safety check?
You're in breach of the law. Fines, prosecution, and imprisonment are possible.
If a tenant is injured or killed by an unsafe gas appliance, you can also be prosecuted under separate criminal offences — including manslaughter in serious cases.
Can I do my own gas safety check?
No. Only a Gas Safe registered engineer can legally work on or inspect gas appliances. This applies to everyone — landlords, business owners, and homeowners.
What is the Gas Safe Register?
The official register of engineers qualified to work on gas in the UK. It replaced CORGI in 2009.
Anyone working on gas must be on the Gas Safe Register. It's the only legally recognised gas register.
How do I check if an engineer is Gas Safe registered?
Ask to see their Gas Safe ID card. It shows their photo, registration number, expiry date, and the specific gas work they're qualified to do.
You can also check at GasSafeRegister.co.uk by entering their name or business.
What does a gas safety check involve?
The engineer checks each gas appliance for:
- Correct operation
- Adequate ventilation
- Tightness of pipework
- Safe combustion (no carbon monoxide leak)
- Working flame failure devices and safety systems
- Flue performance
Anything unsafe is reported and may be disconnected.
How long does a gas safety check take?
About 30 minutes per appliance. A typical home with a boiler, hob, and oven takes around an hour.
How much does a landlord gas safety check cost?
Typically £60–£120 for a standard property with a boiler and one or two other appliances.
Larger properties or commercial premises cost more.
Does a gas safety check include servicing?
No — they're different things.
A safety check confirms the appliance is safe right now. A service is a more detailed inspection and clean-up to keep the appliance running well.
Most landlords combine the two annually. It's cheaper than booking them separately.
What's the difference between a gas safety check and a service?
A safety check is a legal compliance check — required annually for landlords.
A service is preventive maintenance — recommended for the appliance manufacturer's warranty and long-term reliability.
Do I need carbon monoxide alarms?
Yes — in any room with a fixed solid fuel appliance, and (in England) in any room used as living accommodation containing a fixed gas appliance (excluding gas cookers).
Scotland and Wales have their own rules and are stricter on CO alarm placement.
Where should I install a CO alarm?
Within the same room as the appliance. Follow the manufacturer's instructions on exact positioning — usually on a wall or ceiling at a specific height.
What does a Gas Safety Record (CP12) contain?
- Engineer's name, signature, and Gas Safe registration number
- Date of inspection
- Address of the property
- Each appliance, its location, type, and inspection result
- Any defects found and action taken
- Next inspection date
How long should I keep gas safety records?
At least 2 years for landlord records under GSIUR 1998. Most landlords keep them longer for evidence in case of any future dispute.
Do commercial premises need a gas safety check?
Yes. Although not specifically required as an annual "CP12", you must keep gas installations safe under HSWA 1974. Annual inspections by a Gas Safe engineer are the standard way to do this.
Do commercial kitchens need a special gas safety check?
Yes. Commercial catering gas is more complex than domestic — higher pressures, ventilation requirements, interlocks. You need an engineer with the relevant commercial catering qualifications, not just a domestic Gas Safe registration.
What is a gas interlock system?
A safety system in commercial kitchens that turns off the gas supply if the ventilation isn't working properly. It prevents carbon monoxide build-up. Required in most commercial catering installations.
What should I do if I smell gas?
Turn off the gas at the meter. Open windows. Don't use any electrical switches or naked flames. Get out of the building.
Call the National Gas Emergency Service on 0800 111 999 immediately.
What if I think a gas appliance is unsafe?
Stop using it. Call a Gas Safe registered engineer. If the appliance has been disconnected by an engineer with a warning notice, do not reconnect it yourself.
Do I need to keep gas appliance instructions?
Yes — and pass them on to tenants. They explain safe use, including ventilation and what to do if there's a problem.
What's the real purpose of gas safety?
To stop people being killed or injured by gas leaks, explosions, or carbon monoxide poisoning. Everything else is just paperwork to prove you tried.
Need the technical version? Read the gas safety guide for professionals →
This guide provides general information about UK compliance requirements. It is not legal or professional advice. For your specific situation, consult a qualified professional.