Gas safety certificate: the landlord's annual checklist
How often a landlord gas safety check (CP12) is required in the UK, who can issue it, and how to evidence compliance to tenants and councils.
What the law says
Under the Gas Safety (Installation and Use) Regulations 1998, every UK landlord with a gas appliance, flue or pipework in a let property must arrange an annual safety check. The check must be carried out by a Gas Safe registered engineer - no other qualification is accepted.
The output is a Landlord Gas Safety Record, almost always referred to by its old form number, CP12. You must keep the record for at least two years and provide a copy to existing tenants within 28 days of the check, and to any new tenant before they move in.
What gets inspected
All gas appliances supplied by the landlord (boiler, hob, gas fire), the pipework feeding them, and any flue. Tenant-owned appliances are excluded from the certificate itself but the flue serving them must still be checked.
The engineer tests for tightness, burner pressure, ventilation, safety devices and combustion. Anything not safe is classed Immediately Dangerous (ID) or At Risk (AR); ID appliances are disconnected on the spot with the tenant's permission.
When to renew
The annual deadline is 12 months from the previous check, but you can renew up to two months early without losing your anniversary date. Treat the next-due date as a hard deadline - letting a CP12 expire is one of the easiest ways to invalidate landlord insurance and lose a Section 8 possession claim.
CertMyHome stores the renewal date against each property and reminds you 28, 14 and 7 days out so it never lapses.
Evidence to keep
Save the signed CP12 PDF against the property, the engineer's Gas Safe ID number, and proof that you sent it to the tenant (an email timestamp is fine). If you switch tenants mid-year, the new tenant needs the current CP12 before move-in, not the next renewal.
Frequently asked questions
How often does a landlord gas safety check need renewing?+
Every 12 months. You can renew up to two months early without resetting the anniversary date.
Who can issue a CP12?+
Only a Gas Safe registered engineer. Always cross-check their ID card and registration number on the Gas Safe register before they start work.
What happens if my CP12 expires?+
You're in breach of the Gas Safety Regulations 1998. Penalties range from unlimited fines to imprisonment in serious cases, and your landlord insurance is typically void from the expiry date.
Do I need a CP12 for an all-electric property?+
No - if there is no gas supply, no appliance and no pipework, the regulations don't apply. Keep documentary proof that the property is gas-free.