What Is a CP12? The Landlord Gas Safety Certificate Explained

Quick answer: A CP12 is the Landlord Gas Safety Record — the certificate a Gas Safe registered engineer issues after the annual gas safety check. “CP12” is the old CORGI form code; the document is now officially the Landlord Gas Safety Record, but the old name stuck. It lasts 12 months, must be given to tenants, and must be kept for at least 2 years.

Almost every landlord has heard the term “CP12” — usually from an engineer or letting agent — without being entirely sure what it is. The confusion is understandable: the name is a relic, and the document goes by three different titles. This guide clears it up.

What “CP12” actually stands for

CP12 means CORGI Proforma 12. CORGI (the Council for Registered Gas Installers) was the UK's gas safety registration body until 2009, when the Gas Safe Register took over. CP12 was simply the form number for the landlord's annual gas safety check.

The registration scheme changed, but the form number was so widely used that it never went away. So when an engineer says “I'll email you the CP12,” they mean the same document the law calls a Landlord Gas Safety Record.

Three names, one document

All of these refer to exactly the same certificate:

• CP12 — the legacy industry term
• Landlord Gas Safety Certificate — the common plain-English name
• Landlord Gas Safety Record — the term used in the regulations

There is no legal difference between them. If a managing agent asks for your “gas certificate” and the engineer hands you a “CP12,” you have the right document.

What a CP12 records

A valid CP12 must contain every field the Gas Safety (Installation and Use) Regulations 1998 require:

1. The date of the check
2. The address of the property
3. The landlord's (or agent's) name and address
4. A description and location of each gas appliance and flue checked
5. The safety check results for each appliance
6. Any defects found and the remedial action taken or advised
7. Confirmation the checks met the regulations
8. The engineer's name, Gas Safe registration number, and signature

If any field is blank, the record is incomplete — and an incomplete CP12 can be challenged by a tenant, a council, or a buyer's solicitor. For the full breakdown of each landlord duty, see the complete gas safety certificate guide.

How to read the safety classifications

If the engineer finds a problem, the CP12 will carry one of three codes. Knowing what they mean tells you how urgently you must act:

• ID (Immediately Dangerous) — the appliance must be turned off at once and not used until repaired.
• AR (At Risk) — a fault that could become dangerous; the appliance should be made safe quickly.
• NCS (Not to Current Standards) — safe to use now but should be upgraded at the next opportunity.

A clean CP12 with no codes against any appliance is what you are aiming for each year.

CP12 vs a boiler service

A common and costly misunderstanding: the CP12 is not a boiler service. The gas safety check confirms the appliance is safe to operate; a service is preventative maintenance to keep it running efficiently and protect the warranty. A boiler can pass its CP12 and still be overdue for a service. Many landlords arrange both in the same visit, but they are separate jobs and the CP12 does not prove a service was done.

How long to keep each CP12

The regulations require you to keep gas safety records for at least 2 years. In practice, keep every CP12 for as long as you own the property — buyers' solicitors, selective-licensing inspectors and insurers routinely ask for the last few years. A digital folder per property, with one sub-folder per year, is the method most letting agents use.

Frequently asked questions

Is a CP12 the same as a gas safety certificate?

Yes. CP12 was the form code under the old CORGI scheme. Today the document is officially called the Landlord Gas Safety Record, but engineers, agents and landlords still call it a CP12. The legal requirements are identical.

How long is a CP12 valid for?

A CP12 covers a 12-month period from the date of the check. A new check must be carried out before it expires. Since 2018 you can complete the next check up to two months early without losing the original expiry date.

Who can issue a CP12?

Only a Gas Safe registered engineer qualified for the category of appliance being checked. A record issued by anyone not on the Gas Safe Register is legally worthless.

Do I get a CP12 if my rental has no gas?

No. The requirement only applies to properties with landlord-supplied gas appliances or pipework. Keep written evidence the property is all-electric instead.

Reviewed by Jamie Dawson, Editor of Logbook.co.uk. Jamie runs a UK fire & security firm and writes from first-hand experience of property-compliance record-keeping. This guide is general information for landlords, not legal advice. Corrections: corrections@logbook.co.uk