Landlord gas safety certificate: when, how, and what it costs

Every year. That's the short answer. Every year, for every gas appliance in a rented property, you need a valid gas safety certificate — commonly called a CP12 or gas safety record.

If you're new to being a landlord, or if you've been managing a property without any gas appliances and are now wondering whether this still applies to you: the short answer is still yes, if there's a gas boiler, gas hob, or any gas-fired appliance in the property.

This guide covers what the certificate is, who can issue it, what it costs, what the inspection involves, and what to do with the record once you have it.

What is a landlord gas safety certificate (CP12)?

The gas safety certificate — formally known as a CP12 or gas safety record — is a document issued by a Gas Safe registered engineer after inspecting and testing all gas appliances, flues, and pipework in a rental property. It confirms that each appliance is operating safely at the time of the inspection.

The certificate records:

The property address
The appliances and their locations
The engineer who inspected them
The date of inspection
The next due date (typically 12 months from the inspection date)
Any defects found and any remedial work carried out

A copy of the certificate must be provided to any new tenant before they move in, and to existing tenants within 28 days of the annual inspection.

How often do landlords need one?

Every 12 months. Without exception. Unlike some other compliance certificates (EICR is every 5 years), gas safety certificates are annual by law.

If you install a new gas appliance mid-tenancy, you have 14 days to get it inspected and add it to the gas safety record.

If a tenancy spans more than one certification year, the certificate must be renewed before it expires — even if the tenant has been in place for years without issue. There is no provision for a "rolling" certificate or an extension.

Who can issue a gas safety certificate?

Only a Gas Safe registered engineer can issue a CP12. Gas Safe is the official gas registration body in the UK — anyone working on gas appliances legally must be on the Gas Safe Register.

You can check an engineer's registration number on the Gas Safe Register website. Always ask to see their card if you're booking someone you haven't used before. The card shows their registration number, the date they were assessed, and the types of work they're qualified to do.

Do not use a non-registered engineer — the certificate would be invalid, and you'd have no defence if something went wrong.

How much does it cost in 2026?

Gas safety inspections are typically priced as a flat fee per property, not per appliance. As a rough guide:

Standard inspection (1–4 appliances): £60–£120
Larger property or HMO: £100–£180
Additional appliances or complex setups: £15–£30 per extra appliance on top of the base fee

Prices are higher in London and the South East, and can be lower in parts of Scotland. If the property has an old or complex heating system, budget more time and potentially more cost — the engineer may need to spend longer on the inspection.

Many landlords bundle the gas safety inspection with an annual boiler service. This typically costs a little more but means the boiler is also maintained — which can prevent breakdowns in winter and is often a condition of the boiler manufacturer's warranty.

What does the inspection actually cover?

The Gas Safe engineer will:

Inspect all gas pipework for integrity and leaks
Test all gas appliances for safe operation
Check that flues and ventilation are clear and functioning correctly
Verify that safety devices (flame failure devices, etc.) are working
Check the tightness and soundness of all joints
Issue a written certificate if everything passes

If a fault is found, the engineer will note it on the certificate and may be able to repair it on the spot if it's a minor issue. For a serious fault, they may isolate the appliance and advise that it not be used until repaired.

What to do with the certificate once you have it

Give a copy to your tenant within 28 days of the inspection (or before they move in for new tenancies)
Keep a copy yourself for at least 2 years after the certificate expires
Set a reminder now for the next inspection — at least 4 weeks before the expiry date

On that last point: if your tenant changes, you don't need to get a fresh inspection just because a new person has moved in. The existing certificate transfers with the property, as long as it's still valid. What you do need to do is give the new tenant a copy of the current certificate within 28 days of them moving in.

Common pitfalls

Missed deadline. The most common failure. The certificate lapses, and now you're renting without a valid gas safety record. This is a criminal offence under the Gas Safety (Installation and Use) Regulations 1998, and the penalty can include a fine and up to six months' imprisonment for the most serious cases.

Engineer not Gas Safe registered. Always check. A certificate from someone not on the Gas Safe Register is not valid.

Tenant refuses access. If a tenant refuses access for a gas safety inspection, you must make and document at least three attempts to gain access before you can rely on the "reasonable access refused" defence. Document everything in writing. It's worth involving your letting agent or a solicitor if a tenant is persistently blocking access.

No gas appliances but gas supply still connected. If the property has a gas supply but no gas appliances — some older properties have a gas meter but no gas-fired central heating — the regulations still require an annual gas safety check on the pipework. Technically, a Gas Safe engineer should inspect and issue a "no gas appliances" certificate. Check with your gas supplier or a Gas Safe engineer if you're unsure.

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This guide reflects current UK gas safety regulations as of mid-2026. It is not legal advice. For specific queries about your obligations, consult a Gas Safe registered engineer or a qualified letting agent.