CP12 / Landlord Gas Safety Certificate Explained

Every winter a landlord rings you in a panic because a letting agent has asked for "the CP12" and theirs has expired. It is one of the most common, most repeatable jobs on a gas engineer's calendar — and one of the easiest to turn into steady, recurring work. But only if you understand exactly what the certificate covers, who is legally responsible, and how to price it so it is worth your time.

This guide breaks down the CP12 landlord gas safety certificate in plain English: what it is, who needs one, what you check, and how to build it into a profitable part of your business.

What a CP12 Actually Is

CP12 is the old industry shorthand for the Landlord Gas Safety Record. "CP12" was originally a CORGI form number, and the name stuck even though the format has changed over the years. Today you will hear it called any of:

• CP12
• Landlord Gas Safety Certificate
• Landlord Gas Safety Record
• Gas Safety Record

They all mean the same document: a record confirming that the gas appliances, fittings and flues in a rented property have been checked and are safe to use.

It is not the same as a boiler service. A service is a maintenance job; the gas safety check is a safety inspection required for let properties. The two are often done in the same visit, but they are separate pieces of work — and you should price them as such.

Only a Gas Safe registered engineer can carry out the check and issue the record. If you are not yet on the register, our Gas Safe registration guide walks through how to get there.

Who Needs One and How Often

The legal duty sits with the landlord, not the tenant. In broad terms, anyone letting out a property with gas appliances, fittings or flues has a duty to keep them maintained and to have an annual gas safety check carried out by a Gas Safe registered engineer. That covers private landlords, letting agents acting on their behalf, housing associations and similar.

As a rough guide:

• The check is carried out every 12 months.
• The landlord must give the tenant a copy of the record, usually within a set number of days of the check, and to new tenants before they move in.
• Records normally need to be kept for at least two years.

The exact timeframes and duties are set out in the Gas Safety (Installation and Use) Regulations, and the rules can differ for HMOs, parts of the UK outside England, and some appliance types. Always point landlords to the current official guidance from the HSE and Gas Safe Register rather than relying on what "used to be" the rule — the wording is updated from time to time.

Tip: there is a useful grace window in the regulations that lets the annual check be done up to two months before the expiry date without losing the original anniversary date. Doing checks slightly early keeps your diary predictable and stops landlords drifting out of compliance.

What the Check Covers

A landlord gas safety check is a defined set of safety checks on the gas installation. As a working summary, you are confirming for each appliance and flue:

• The appliance is correctly and safely installed.
• It is operating correctly and burning gas safely (this is where your combustion analysis matters — see combustion analysis readings explained if you want a refresher).
• Flueways and chimneys are clear and the products of combustion are removing safely.
• Ventilation is adequate.
• Safety devices are working.
• There are no signs of unsafe operation.

Landlord-owned appliances must be checked. You also record any tenant-owned appliances you reasonably can, and flag anything that looks unsafe.

Recording the result

The record lists every appliance and flue checked, the results, any defects found, and any work or warnings issued. If you find something dangerous you follow the usual unsafe situations procedure — classifying it, getting permission to make safe where appropriate, and issuing the relevant warning notice. None of that changes just because it is a let property; the CP12 simply documents the outcome.

How to Price CP12 Work

A standalone landlord gas safety check is a relatively quick, predictable job, which is why pricing it well matters. Go too low and you are doing skilled, liability-carrying work for the price of a coffee; go too high in isolation and a landlord with a portfolio will shop around.

A few principles that keep it profitable:

• Price the check and the service separately. Many landlords want both. Quote a single visit but show the two lines so the value is clear.
• Offer portfolio pricing. A landlord or agent with ten properties is worth far more than a one-off. A modest per-property rate across a block beats a premium one-off rate you only get once.
• Factor in travel and access. Void periods, key collection from agents and missed appointments eat your margin. Build realistic time in.
• Charge for re-visits. If you have to return because a tenant was not in, that is chargeable.

As a rough guide, standalone landlord gas safety checks in much of the UK sit in the region of a typical short visit rate, with the service adding to that — but rates vary widely by area and by how many properties are bundled. Work out your own number from your real costs; our trade pricing formula shows how.

Turning One-Off CP12s Into Recurring Revenue

Here is the part most engineers leave on the table. A CP12 is, by definition, an annual job. The same property needs another one in twelve months. If you let that renewal depend on the landlord remembering, you are gifting next year's work to whoever rings them first.

This is where a job-management system earns its keep. With Gaffer you can:

• Store every certificate against the property and customer, so you are never digging through a van full of paper when an agent asks for a copy.
• Set the next check date automatically and have a reminder go out to the landlord — and a job appear in your diary — before it expires.
• Send the record to the landlord the moment you have finished, instead of weeks later.

That single habit — automated annual reminders — quietly converts one-off checks into a predictable round. We go deeper on it in automating annual gas service reminders, and on collecting the money cleanly in how to get paid faster.

Letting agents in particular value an engineer who turns up on time, sends the certificate immediately and never lets a property lapse. Become that engineer for one agency and you can pick up a whole portfolio.

FAQs

Is a CP12 the same as a gas safety certificate?

Yes. "CP12" is industry shorthand for the Landlord Gas Safety Record, also called the gas safety certificate or gas safety check record. They all refer to the same document confirming the gas appliances in a let property have been checked as safe.

Who is legally responsible for getting a CP12?

The landlord. Letting agents often arrange it on the landlord's behalf, but the legal duty to have the annual check carried out and to give tenants a copy sits with the landlord, not the tenant.

How often does a landlord gas safety check need doing?

Generally every 12 months. There is a grace period that allows the check to be done up to two months early without losing the original renewal date. Always confirm the current rules with the HSE and Gas Safe Register.

Can any plumber issue a CP12?

No. Only a Gas Safe registered engineer who is qualified for the relevant appliance types can carry out the check and issue the record. Working on gas without being on the register is illegal.