What is a CP12 certificate?
CP12 is the industry shorthand for the Landlord Gas Safety Record — the certificate a Gas Safe registered engineer issues after inspecting the gas appliances, flues and pipework in a rental property. If you let a property with any gas appliance anywhere in the UK, you must renew it every 12 months.
Why is it called a CP12?
The name comes from CORGI Proforma 12 — the numbered form the old Council for Registered Gas Installers used for landlord gas safety records. CORGI was replaced by the Gas Safe Register in 2009, but the CP12 name stuck. Today "CP12", "gas safety certificate", "landlord gas certificate" and "Landlord Gas Safety Record" all mean the same document.
What does a CP12 include?
During the inspection, a Gas Safe registered engineer will:
- Check every gas appliance — boiler, hob, gas fire — for safe operation, correct pressure and complete combustion.
- Run a tightness test on the supply pipework to rule out leaks.
- Inspect flues and chimneys for correct operation and sealing.
- Check ventilation and air supply to each appliance.
- Confirm a working carbon monoxide alarm in every room with a fixed combustion appliance.
The finished CP12 lists every appliance inspected, any defects found, and the engineer's Gas Safe registration number. You keep a copy, your tenant gets a copy within 28 days (or before move-in for new tenants), and you must retain records for at least 2 years.
Who can issue a CP12?
Only an engineer on the Gas Safe Register — the legal replacement for CORGI registration. Always check the engineer's ID card; an inspection by anyone else has no legal standing and leaves you exposed to the full penalties for non-compliance.
How much does a CP12 cost?
A standard CP12 with one appliance typically costs £55–£85 in 2026. GetCerted charges a flat £60 plus £10 per gas appliance, fixed before the engineer arrives — so a typical boiler-and-hob rental is £80. See the full gas safety certificate cost guide for prices by appliance count.
What happens if my CP12 lapses?
- HSE fines from £6,000 per appliance, with unlimited fines and prosecution in serious cases.
- An invalid Section 21 — you can't lawfully regain possession without a valid CP12 on file.
- Voided landlord insurance — most policies require a current certificate.
Renewing early never costs you cover: renew in the final 2 months and the new certificate runs from the old expiry date, not the inspection date.
Need a CP12 in Blackpool or the Fylde?
We book Gas Safe registered engineers across Blackpool, Lytham, St Annes and the wider Fylde within 48 hours, with the certificate delivered to your digital vault the same evening. Read the full Landlord Gas Safety Certificate page, or send us the postcode below for a fixed price.