Gas Safety Certificate (CP12) in Wandsworth

A Landlord Gas Safety Record — historically known as a CP12 after the CORGI Proforma 12 form — is the official record of the annual gas safety check that landlords must commission under the Gas Safety (Installation and Use) Regulations 1998. It lists every gas appliance and flue checked, the defects identified, and the remedial action taken. Only a Gas Safe registered engineer can carry out the check and issue the record. Landlords must give a copy to existing tenants within 28 days and to new tenants before they move in.

The engineer inspects and tests each gas appliance and flue: checking appliances are burning gas correctly and operating at the right pressure, that flues and chimneys are clear and safely removing combustion products, that ventilation is adequate, and that safety devices work. They also carry out a visual inspection of the pipework and a tightness test to check for leaks. Any appliance found to be unsafe is classified (Immediately Dangerous, At Risk, or Not to Current Standards) and may be disconnected with your agreement.

Failing to comply with the Gas Safety Regulations is a criminal offence prosecuted by the Health and Safety Executive, with unlimited fines and up to six months' imprisonment for the most serious breaches. Beyond prosecution, a landlord without a valid record cannot serve a valid Section 21 notice, will have property licence applications refused or delayed, and may invalidate their landlord insurance. If a tenant is harmed by a gas appliance that was not checked, the landlord can face manslaughter charges in the worst cases.

The check must be carried out every 12 months. Under Regulation 36A, landlords benefit from an MOT-style renewal window: if the new check is done in the final two months before the existing record expires, the new record keeps the original expiry date — so you never lose time by renewing early. Booking 10–11 months after the last check avoids the risk of a compliance gap caused by access problems or engineer availability.

Yes. Every London borough requires a current Landlord Gas Safety Record as part of an HMO, additional, or selective licence application where the property has a gas supply. Councils routinely reject or delay applications with expired or missing gas certificates. If you are applying under a new scheme — such as Harrow's selective licensing scheme starting 6 July 2026 or Hillingdon's additional HMO licensing from 24 August 2026 — arrange the gas safety check before you start the application so the certificate is in date when you submit.