CP12 vs gas safety certificate: what's the difference?

The landlord asks for a gas safety certificate. The engineer says they'll do the CP12. The paperwork that arrives says Landlord Gas Safety Record. Nobody has misunderstood anybody; the same document has collected three names over the years, and this guide untangles where each came from and the one distinction that does matter.

Why does the same document have three names?

The confusion is purely in the language. “CP12” comes from the old CORGI form number and stuck in the trade long after CORGI itself was replaced by the Gas Safe Register in 2009. The document's formal name today is the Landlord Gas Safety Record. Landlords and tenants tend to say “gas safety certificate”, and search engines agree with them. They all describe the same thing: the record of an annual gas safety check on a rented property's appliances and flues.

Is there any legal difference between the names?

None. The law never mentions “CP12” or “certificate” at all. What the Gas Safety (Installation and Use) Regulations 1998 require is a record of each safety check with the substance on it: the appliances and flues checked, the defects found and action taken, the dates, the address, and the engineer's name, registration number and signature. Any document carrying that content, issued by a Gas Safe registered engineer who did the check, satisfies the duty, whatever its header calls it. The name is habit; the content is the law.

Which gas safety record does a landlord actually need?

The meaningful difference isn't in the name but in who the check is for:

• Landlord Gas Safety Record (CP12): the legally required annual record for a rented property.
• Homeowner gas safety record: the same style of check arranged voluntarily by an owner-occupier, no legal duty, but a genuine safety check.
• In both cases the check is carried out and the record issued by a Gas Safe registered engineer.

The line between the two matters most at the moment it moves: the day an owner-occupier becomes a landlord. A voluntary homeowner check was a good habit; the landlord check is a legal duty with deadlines attached, tenant copies, renewal every 12 months, records kept for two years. If you're about to let your own home, tell the engineer, so the check is booked and recorded with those duties in mind.

What other gas documents might you be handed?

Part of the confusion is that the CP12 lives among a small family of gas paperwork, and the names blur into each other. The documents you're most likely to meet:

• CP17, the Non-Domestic Gas Installation Safety Report: the commercial equivalent of the CP12, for shops, restaurants, offices and other non-domestic premises, issued by an engineer holding commercial competencies.
• Boiler service record: proof of maintenance on one appliance, done to the manufacturer's schedule. It isn't a safety check of the property and doesn't substitute for the CP12, but it's the paperwork that keeps warranties alive.
• Benchmark commissioning checklist: completed when a new boiler is installed and kept with the appliance for its working life, with the annual service entries logged in it.
• Building Regulations compliance certificate: arranged through Gas Safe registration when a new appliance is installed, and the document buyers' solicitors ask for by name during conveyancing.
• Warning notice: attached under the industry's unsafe situations procedure when an appliance is judged dangerous, recording that it was disconnected or turned off and why.

None of these replaces the landlord's annual record, and the annual record replaces none of them. When someone asks for “the gas certificate”, the fastest way to the right document is to ask what they need it for.

What should you check when you're handed one?

Does it matter what your paperwork calls it?

Not to the law, but the naming muddle has a practical cost: records filed under three different names are records nobody can find. Manifold sidesteps it by tying every record to the property and the appliance rather than the label, so whether the landlord asks for “the CP12”, “the gas cert” or “that safety thing”, the answer is the same search box and the same few seconds. Engineers issue the record from their phone at the job; the landlord's copy arrives the moment it's signed.