Northampton · West Northamptonshire
What Is a CP12? The Plain-English Guide
CP12 is the traditional name — from the old Council for Registered Gas Installers (CORGI) form numbering — for the Landlord Gas Safety Record. The certificate itself is issued by the engineer after the statutory annual check.
What the engineer actually does
The check is a safety inspection, per the Gas Safety (Installation and Use) Regulations 1998:
1. Flue flow and spillage test — combustion products are leaving the property properly. 2. Gas rate and working pressure — the appliance is burning at the right rate. 3. Burner pressure checks against manufacturer data. 4. Operation and safety devices — flame supervision, thermostats, cut-outs working. 5. Visual condition — supports, pipework, flue routes, ventilation provision. 6. Appliance-by-appliance results — each gas appliance in the check scope gets its own line: Gas Safe (satisfactory), At Risk (AR) or Immediately Dangerous (ID).
The three verdicts that matter
- ID (Immediately Dangerous): must not be used. The engineer will disconnect or label it. Fix before any further use — this is not negotiable.
- AR (At Risk): must not be used until repaired. Similar urgency, documented with the defect.
- NCS (Not to Current Standards): safe to use, doesn't comply with modern standards — schedule an upgrade, not an emergency.
What it is NOT
- Not a service. The CP12 proves safety on the day. Servicing cleans, adjusts and maintains — and keeps warranties valid.
- Not optional for vacant properties. The duty continues between tenancies.
- Not transferable between properties. Each property gets its own record.