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

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

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 that you provide.

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

What is a landlord gas safety certificate (CP12)?

The document is formally called the Landlord Gas Safety Record. "CP12" is the name of an old CORGI form, and "gas safety certificate" is what most people still say — all three mean the same thing. It is issued by a Gas Safe registered engineer after checking the gas appliances and flues you provide in a rental property, and confirms that each one was operating safely at the time of the check.

The record must show:

The property address
A description and location of each appliance and flue checked
The engineer's name, registration number and signature
The date of the check
The landlord's name and address (or the agent's)
Any defect found and any remedial action taken
Confirmation that the check covered the matters the regulations require

A copy must be given to any new tenant before they move in, and to existing tenants within 28 days of the check.

How often do landlords need one?

Every 12 months. Each appliance and flue you provide must be checked within 12 months of being installed, and then at intervals of no more than 12 months.

There is one piece of flexibility, introduced in 2018, that is worth knowing because it makes life easier: if you have the check done 10 to 12 months after the previous one, the new record keeps the original expiry date. In other words you can book the engineer up to two months early without losing any time on the certificate. If you have the check done earlier than that, or later, the new record runs 12 months from the date of the new check. HSE expects you to be able to show you met the timescales, so keep the dates on file.

If you install a new gas appliance or flue mid-tenancy, it must be checked within 12 months of installation. In practice most landlords simply add it to the next annual check.

Who can issue a gas safety certificate?

Only a Gas Safe registered engineer can carry out the check and complete the record. Gas Safe Register is the official gas registration body for Great Britain — anyone working on gas appliances legally must be on it.

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 record would be invalid, and you'd have no defence if something went wrong.

How much does it cost?

There is no official price list. Gas safety checks are typically priced as a flat fee per property, not per appliance. As an indicative guide from quotes we have seen in 2026:

Standard check (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. 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 check.

Many landlords bundle the gas safety check 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:

Test each gas appliance you provide for safe operation
Check that flues and ventilation are clear and functioning correctly
Verify that safety devices (flame failure devices, etc.) are working
Look for signs of leaks or unsafe pipework
Complete the Landlord Gas Safety Record

If a fault is found, the engineer will note it on the record 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.

Separately from the annual check, you have an ongoing duty to keep the gas pipework, appliances and flues you provide maintained in a safe condition. Most landlords cover this by having the engineer look over the installation during the annual visit.

What to do with the certificate once you have it

Give a copy to your tenant within 28 days of the check, or before they move in for new tenancies
Keep a copy yourself for at least 2 years — and if you used the 10-to-12-month renewal window, keep it until two further checks have been done
Set a reminder now for the next check — booking 4–8 weeks before expiry keeps you inside the renewal window

On that last point: if your tenant changes, you don't need a fresh check just because a new person has moved in. The existing record stays valid for the property. What you do need to do is give the new tenant a copy of the current record before they move in.

Common pitfalls

Missed deadline. The most common failure. The record lapses, and now you're renting without a valid gas safety check. This is an offence under the Gas Safety (Installation and Use) Regulations 1998, and HSE's guidance is that a breach "could result in a substantial fine and/or a custodial sentence".

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

Tenant refuses access. You have to take all reasonable steps to get the check done. HSE's guidance is to write to the tenant explaining why the check is needed, leave a notice if you can't get in, and keep a record of every attempt and every letter. HSE inspectors will look for at least three documented attempts. It is ultimately for a court to decide whether what you did was reasonable, so paper trail matters. Involve your letting agent or a solicitor if a tenant is persistently blocking access.

Tenant's own appliances. Your duty covers the appliances and flues you provide. Appliances the tenant owns are not part of your annual check, though any flue they connect to still is.

Gas supply but no landlord appliances. If the property has a gas meter and pipework but you provide no gas appliances or flues, the annual check requirement does not bite — the check is for appliances and flues. You still have the duty to keep the pipework safe, so having a Gas Safe engineer tightness-test the installation periodically is sensible, and if you're unsure what's on the property, ask one.

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This guide was reviewed against the Gas Safety (Installation and Use) Regulations 1998 and HSE's landlord guidance on 10 October 2026. It is general information, not legal advice. For specific queries about your obligations, consult a Gas Safe registered engineer or a qualified letting agent.