What is a CP12? Landlord gas safety explained

CP12 is the historic form code from the CORGI era — Council for Registered Gas Installers, the gas safety scheme that operated until 2009. The official current name is the Landlord Gas Safety Record, issued under Regulation 36 of the Gas Safety (Installation and Use) Regulations 1998. Almost everyone in the UK rental industry — landlords, agents, engineers, councils — still calls it the CP12, and Gas Safe registered engineers will still recognise the term and issue you what you ask for.

It's a yearly check, required on every property let to a tenant under any tenancy agreement, covering every gas appliance the landlord is responsible for plus the gas pipework and flues serving them. The engineer inspects, tests, and issues a written record listing the appliances, the work done, any defects found, and a satisfactory or unsatisfactory verdict for each item.

A typical CP12 visit on a 1- to 3-bed flat or house takes 30–60 minutes and covers: the boiler (combustion analysis, flue gas reading, gas valve operation, flue integrity and termination), the gas hob and oven if landlord-supplied (burner condition, flame picture, ignition), any gas fire (flue, ventilation, oxygen-depletion sensor), gas water heaters where applicable, the gas meter and emergency control valve, the visible gas pipework, and the ventilation provision for any room containing a gas appliance.

The engineer does not test appliances the tenant owns (their own portable heaters, their own gas barbecue, etc.) — those aren't the landlord's responsibility under the regulations. The record specifically lists the appliances inspected; anything not listed is by implication not covered.

Only Gas Safe registered engineers can legally carry out the check and issue the record. Gas Safe replaced CORGI as the UK gas safety scheme on 1 April 2009 — a CORGI-only certificate from any date after that is not a valid CP12. Every Gas Safe engineer carries an ID card with a photograph, registration number, and the categories of gas work they're qualified for. Categories matter: an engineer registered for natural gas isn't necessarily registered for LPG, and an engineer registered for cookers isn't necessarily registered for boilers.

Always check the engineer's Gas Safe number on the Gas Safe Register (gassaferegister.co.uk) before authorising work. The register lookup is free, instant, and gives you the registered categories so you can confirm the engineer is qualified for the appliances at the property.

The CP12 is required every 12 months. If the previous record was issued 12 March 2026, the next must be in place by 12 March 2027. Letting an existing CP12 expire while a tenancy is ongoing is a Reg 36 breach — not a paperwork inconvenience but a criminal offence under the Health and Safety at Work etc Act 1974. Penalties on conviction include unlimited fines and, in serious cases, imprisonment.

There's one administrative concession that's genuinely useful for portfolio landlords. Under Reg 36(3), if you carry out the check up to 2 months before the existing record expires, the new record retains the original anniversary date. So a CP12 originally dated 12 March 2026, re-checked on 14 February 2027 (within 2 months), still expires on 12 March 2028 — not 14 February 2028. This lets portfolio landlords cluster CP12 visits for 5–10 properties on the same engineer day without each property's anniversary date drifting forward year by year.

Access for a CP12 is one of the more common landlord-tenant friction points. Section 11 of the Landlord and Tenant Act 1985 implies a right of access for repairs and maintenance with 24-hour written notice, but a tenant who refuses access can't simply be overridden — entry without consent could constitute trespass or harassment under the Protection from Eviction Act 1977.

The standard playbook is documented. First, written request with proposed dates (email is fine). Second, written follow-up with formal 24-hour notice referencing Section 11 and Reg 36. Third, if access is still refused, written confirmation that the landlord has fulfilled their reasonable obligations and that the tenant's refusal is on record. Some landlords seek an injunction in the County Court to compel access — this is uncommon but available where the tenant is genuinely unreasonable.

The key for compliance is that you've made all reasonable attempts to gain access and have written evidence of the dates, methods, and tenant responses. The Health and Safety Executive's enforcement position has been pragmatic on this — a landlord with documented attempts and a tenant who's actively refusing is in a better position than one with no paper trail. None of this is legal advice; for specific cases consult a solicitor or your local authority's housing team.

Typical 2026 UK pricing: £60–£120 for the CP12 alone on a single boiler property; £80–£150 if a hob, oven, or fire is also being checked. London rates run roughly 15–25% above the UK average. Bundled with an annual boiler service (which the manufacturer's warranty often requires anyway), the combined price typically sits at £110–£180.

Most landlords schedule the CP12 alongside the boiler service for efficiency. Engineers offering both can usually complete a typical 2-bed flat in 60–90 minutes, with the certificate issued by email the same day or next morning.