Gas safety certificates (CP12): what landlords must do every year
Legal basis: Gas Safety (Installation and Use) Regulations 1998 (SI 1998/2451). Non-compliance can result in an unlimited fine or up to six months' imprisonment, and blocks certain Section 8 possession grounds.
The annual inspection requirement
Under the Gas Safety (Installation and Use) Regulations 1998, landlords who let residential properties with gas appliances must arrange a gas safety check every 12 months. The check must be carried out by a Gas Safe registered engineer. You can verify any engineer's registration at gassaferegister.co.uk.
The check covers all gas appliances, pipe-work and flues in the property. On completion, the engineer issues a Landlord Gas Safety Record — commonly called a CP12 certificate, though the official terminology is Gas Safety Record.
What must be on the certificate
A valid Gas Safety Record must include:
- A description of and the location of each appliance or flue inspected
- Any defect identified and the action taken to fix it
- Confirmation that the appliance or flue has been checked for gas tightness, safe operation, proper ventilation and safe flue operation
- The date the check was carried out
- The name, registration number and signature of the Gas Safe engineer
- The address of the property
When you must give it to tenants
The regulations specify two scenarios:
- New tenants: The Gas Safety Record must be given to them before they move in, or before they enter into the tenancy agreement — whichever comes first.
- Existing tenants: A copy of the new record must be given within 28 days of the annual check being carried out.
You must keep records of each gas safety check for at least two years.
Possession impact: If you have not served the Gas Safety Record on your tenant, you may not be able to rely on Section 8 Grounds 1 to 8. This was the rule under Section 21 and the Renters' Rights Act carries the same prescribed document requirements into the Section 8 framework.
Renewing before the 12-month anniversary
You are allowed to carry out a new gas safety check up to two months before the current certificate expires without losing the annual cycle. For example, if your certificate expires on 31 August, you can have the new check done from 1 July onwards and your new 12-month period will still run from 31 August. This is useful for scheduling flexibility.
What happens at an unsafe appliance
If the engineer identifies an unsafe appliance, they are required under the regulations to issue an Unsafe Situation notice. They may cap the gas supply or label the appliance as "immediately dangerous" or "at risk." As landlord, you must not allow the appliance to be used until it has been repaired or replaced and re-inspected. You cannot ignore an engineer's safety finding.
Common compliance failures
- Having the check done but forgetting to give a copy to the tenant within 28 days
- Letting the certificate lapse even by a few days
- Using an unregistered engineer (the certificate is invalid and potentially dangerous)
- Not covering all gas appliances in the property, including appliances the tenant brought in if connected to the gas supply
Set a reminder 6 weeks before your certificate expiry date. That gives you time to book an engineer, complete the check and serve the new certificate on the tenant within the 28-day window — all without any gap in compliance.