CP12 Gas Safety Certificate: the complete guide for landlords & engineers
The CP12 — officially the Landlord Gas Safety Record — is the certificate a Gas Safe registered engineer issues after the annual safety check that UK law requires on every rented property with gas appliances. Here's what it covers, what must be on it, and the rules landlords and engineers actually get caught out by.
What is a CP12?
Under the Gas Safety (Installation and Use) Regulations 1998 (GSIUR), landlords must have every gas appliance and flue they provide checked for safety at least every 12 months by a Gas Safe registered engineer. The record of that check is the Landlord Gas Safety Record — still universally known by its old CORGI form number, CP12.
It is not optional and it is not a service: a safety check and a service are different jobs. The CP12 records the safety check; many engineers sensibly do both visits together.
What the engineer checks
During the check, the engineer examines each appliance and flue against the standards set out in the regulations, including:
- Correct operating pressure and heat input
- Adequate ventilation for the appliance
- Flue flow and safe removal of combustion products, and flue termination
- Operation of safety devices
- Physical stability, connections and general condition
What must legally be on the certificate
GSIUR regulation 36(3)(c) sets the minimum content of the record. A valid CP12 must include:
- The date of the check and the address of the property
- The landlord's (or agent's) name and address
- A description and location of every appliance and flue checked
- Any safety defect identified and the remedial action taken or required
- Confirmation the check covered the required examinations
- The engineer's name, signature and Gas Safe registration number
How long it lasts — and the renewal rule engineers should know
A CP12 is valid for 12 months. Since 2018, landlords can have the renewal check done in the final two months before expiry and keep the original expiry date — the "MOT-style" rule — so there is no need to wait until the last minute and no penalty for renewing early within that window.
A copy must be given to existing tenants within 28 days of the check, and to new tenants before they move in. Landlords must keep records for at least two years.
Producing CP12s without the paperwork pain
For engineers, the admin is the painful part: filling the form on site, getting it to the landlord, tracking every property's expiry date, and chasing next year's booking. TradeHub OS generates the CP12 on your phone with your Gas Safe number embedded, captures a drawn signature, emails it instantly, links it to the job, quote and invoice, and automatically reminds the landlord 30 days before expiry — so the renewal comes back to you, not whoever texts first.
This guide is general information for UK trades and landlords, not legal advice. Always refer to the current regulations and official guidance from the HSE, Gas Safe Register or your competent-person scheme.
