Gas safety records

How do you read a CP12?

A CP12, or Landlord Gas Safety Record, lists every appliance and flue with its make, model, type and location, the safety checks done, whether each passed or failed, the check date and next-due date, and the engineer's name, Gas Safe licence number and signature. Check the next-due date first.

Reviewed by Jordan Valentine-Dunn, Gas Safe registered engineer · Portsmouth Gas Heating · Last reviewed July 2026

A CP12, properly called the Landlord Gas Safety Record, can look busy, but it follows a clear layout. It records every gas appliance and flue in the property, the checks carried out on each, the result, and who did the work. Once you know what each part is for, it is easy to read.

What a CP12 records

For each appliance and flue: the make, model, type and location.
The safety checks carried out: gas tightness, burner pressure or heat input, flue performance, ventilation, safety devices and physical condition.
Whether each appliance passed or failed, and any defects found.
The date of the check and the next check due date.
The engineer's name, Gas Safe licence number and signature.

You do not need to be an engineer to sense-check a CP12. The three things to look at first are: the next check due date, so you know when it expires; whether any appliance is marked not safe to use; and that every gas appliance in the property is actually listed. If one is missing, ask why.

Only a Gas Safe registered engineer can carry out the check and judge whether an appliance is safe. This guide helps you read the record; it is not a substitute for the engineer's on-site assessment.

Frequently asked

What does a CP12 show for each appliance?

For every appliance and flue, a CP12 shows the make, model, type and location, the safety checks carried out, whether it passed or failed with any defects, the check and next-due dates, and the engineer's name, Gas Safe licence number and signature.

What is the most important thing to check on a CP12?

Three things: the next check due date, so you know when it expires; whether any appliance is marked not safe to use; and that every gas appliance in the property is listed. A missing appliance is worth querying with the engineer.

How do I know the CP12 is genuine?

It should carry the engineer's name, Gas Safe licence number and signature. You can check that licence number against the Gas Safe Register. Only a Gas Safe registered engineer can carry out the check and issue a valid record.

Sources

Last reviewed July 2026. This guide is general information, not legal or safety advice, gas safety work must be carried out by an appropriately Gas Safe registered engineer. Rules can change, so check the linked official sources for the current position.

Spend less of your evening on this.

Manifold does CP12s on the doorstep and chases the renewals for you. It’s in early access for UK gas engineers, no card, just your first look.