CP12: The Landlord Gas Safety Record
Every relevant gas appliance and flue in a rented property must be checked for safety every 12 months by a Gas Safe registered engineer, and the record given to the tenant — that record is the CP12.
The Gas Safety (Installation and Use) Regulations 1998 place a legal duty on landlords to keep gas appliances, fittings and flues in their let properties safe and to have them checked annually. The document that evidences that check is the Landlord Gas Safety Record, still widely called the CP12 after the old Corgi form number.
This guide sets out the annual duty, the 12-month cycle and the 28-day renewal window that lets you keep dates aligned, who is allowed to carry out the check, what actually gets inspected, and the record-keeping obligations. It is written for engineers and landlords; the gas check itself must be carried out by a Gas Safe registered engineer.
Key takeaways
- Under the Gas Safety (Installation and Use) Regulations 1998, a landlord must have relevant gas appliances and flues safety-checked every 12 months.
- The check must be carried out by a Gas Safe registered engineer competent for the appliance type; the resulting record is the CP12.
- The record must be given to existing tenants within 28 days of the check and to new tenants at the start of the tenancy.
- There is a 28-day rule for renewals: you can carry out the annual check up to two months (28 days each side is commonly used to stay aligned) before the deadline without losing the original expiry date.
- Landlords must keep copies of gas safety records for at least two years.
The landlord's legal duty
The Gas Safety (Installation and Use) Regulations 1998 make the landlord responsible for the safety of the gas appliances, fittings, pipework and flues they own or that serve the let property. The core duties are: to maintain that gas equipment in a safe condition, to arrange an annual gas safety check on each relevant appliance and flue, and to keep and issue the resulting records.
A relevant appliance is generally one supplied by the landlord for the tenant's use; an appliance the tenant owns is usually outside the check, though the connecting installation pipework and any flue serving it can still fall to the landlord. The duty applies across most residential lettings, with some specific arrangements for houses in multiple occupation and certain other tenures.
The annual 12-month cycle and the 28-day rule
Each relevant appliance and flue must be checked at least every 12 months. In practice a check done exactly on the anniversary can drift, so the regulations allow the annual check to be carried out early without losing the existing expiry date.
Under this arrangement — commonly described as the 28-day rule — if the check is done up to 28 days before the due date, the new certificate runs from the original expiry date, not the date of the early check. Do it more than that window early and you effectively bring the anniversary forward. This lets a landlord book slightly ahead of the deadline and keep the same annual date year after year.
Early check, same expiry
Carry out the annual check within the 28-day window before expiry and the new record still runs from the original due date — so booking a little early does not shorten your compliance year.
Who carries out the check and what is inspected
The check must be done by a Gas Safe registered engineer who is competent (holds the right ACS category) for each type of appliance being checked. Registration and the relevant appliance categories can be verified on the engineer's Gas Safe ID card and via the Gas Safe Register.
For each appliance the engineer confirms it is safely connected and located, checks the operating pressure and heat input (or performance) against the manufacturer's data where appropriate, verifies the provision of combustion air / ventilation, checks flue flow and that products of combustion are being cleared safely (the flue integrity/spillage check), and confirms the operation of safety devices. The overall check also covers the tightness of the installation and that appliances have been left in a safe condition, with any defects classified under the Gas Industry Unsafe Situations Procedure.
The record and record-keeping
The CP12 records the property and landlord details, each appliance and flue inspected with its results, any defects and remedial action, the engineer's name, signature and Gas Safe registration number, and the date of the check and the next due date.
The landlord must give a copy of the record to each existing tenant within 28 days of the check being completed, and to any new tenant before they move in (at the start of the tenancy). Copies must be kept for at least two years. Where an appliance is found unsafe, it must be dealt with under the Unsafe Situations Procedure — for example turned off and labelled with the tenant's permission — and the record must reflect that.
The two-year retention rule
Keep every landlord gas safety record for at least two years, and issue each tenant their copy within 28 days of the check (new tenants get it before they move in). Digital records make both the retention and the reissue trivial.
What happens when something is unsafe
If the engineer finds an appliance or installation that is Immediately Dangerous or At Risk, it is handled under the Gas Industry Unsafe Situations Procedure — typically making the situation safe, turning off and labelling the appliance with the responsible person's permission, and advising in writing. The CP12 records the classification and the action taken.
For the landlord, an unsafe result is not a technicality to be filed away: the duty is to keep the equipment safe, so remedial work must follow promptly and the appliance should not be brought back into use until it has been made safe and re-checked.
Frequently asked questions
Is a CP12 a legal requirement?
Yes. Under the Gas Safety (Installation and Use) Regulations 1998, landlords must have relevant gas appliances and flues safety-checked every 12 months and keep and issue the record. The CP12 is that record.
Can I renew the check before it expires without losing the date?
Yes. If you carry out the annual check within the 28-day window before the due date, the new record runs from the original expiry date rather than the date of the early check, so your annual date stays aligned.
When must the tenant get their copy?
Existing tenants must be given the record within 28 days of the check. New tenants must be given it before they move in, at the start of the tenancy.
How long must a landlord keep the records?
Landlords must keep copies of the gas safety records for at least two years.
Do tenant-owned appliances need checking?
The annual check covers relevant appliances the landlord provides. An appliance the tenant owns is generally outside it, though the installation pipework and any flue serving it can still be the landlord's responsibility to keep safe.
From guidance to action
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