Gas Safety Certificates (CP12): the landlord's guide

The legal requirement

Under the Gas Safety (Installation and Use) Regulations 1998, landlords must ensure that all gas appliances, flues and pipework provided for tenants are maintained in a safe condition and checked for safety every 12 months by a Gas Safe registered engineer. This is one of the most strictly enforced duties in the sector because of the immediate risk to life from carbon monoxide and explosion.

What is a CP12 certificate?

The CP12 — formally the Landlord Gas Safety Record — is the document issued after the annual check. It lists every appliance inspected, the results of the safety checks, any defects identified and the action taken, plus the engineer's Gas Safe registration details. Keep records for at least two years.

Inspection frequency and timing

The check must be carried out within 12 months of the last one. You can have it done up to two months before the deadline without losing the original 'anniversary' date — a useful way to build in slack and avoid accidental lapses.

Landlord obligations

• Arrange an annual safety check by a Gas Safe registered engineer.
• Maintain gas pipework, appliances and flues in safe condition.
• Give existing tenants a copy of the CP12 within 28 days of the check.
• Give new tenants a copy before they move in.
• Keep a copy of each record for at least two years.

Tenant obligations

Tenants must allow reasonable access for the annual check and any maintenance. They should not interfere with appliances or use any that are clearly unsafe. If a tenant repeatedly refuses access, document every attempt in writing — this evidence is essential if you need to demonstrate you took all reasonable steps.

Common mistakes

• Letting the check slip past the 12-month deadline.
• Forgetting to serve the CP12 within 28 days.
• Using an engineer who is not Gas Safe registered for the appliance type.
• Not keeping evidence of access attempts where a tenant blocks entry.

Penalties

Breaches of the gas safety regulations carry an unlimited fine and, in serious cases, imprisonment. The Health and Safety Executive prosecutes the most serious failures. A missing or out-of-date certificate can also undermine a possession claim and void your landlord insurance.

Gas safety expiry calculator