What Is a CP12 Certificate? A Complete Guide for London Landlords
The CP12 Gas Safety Certificate is a legal requirement for all London landlords with gas appliances in rental properties. This guide explains exactly what it covers, who can issue it, how often it is needed and what happens if one is missing.
CP12 Gas Safety Certificate: A Complete Guide for London Landlords
The CP12 Gas Safety Certificate — formally known as a Gas Safety Record — is one of the most important compliance documents a London landlord must hold. Getting it right is not difficult, but getting it wrong carries significant legal and financial consequences. This guide covers everything a landlord needs to know about the CP12, from what it covers to what happens when one lapses.
What Is a CP12 Certificate
A CP12 is a document issued by a Gas Safe registered engineer following a safety inspection of all gas appliances and visible gas pipework in a rental property. "CP12" is a shorthand term derived from an older Gas Safe form reference, though the current document is formally called a Gas Safety Record or Gas Safety Certificate. Both terms refer to the same document. The inspection and certificate are a requirement under the Gas Safety (Installation and Use) Regulations 1998, as amended.
What the Inspection Covers
A CP12 inspection includes a check of every gas appliance in the property: the boiler, gas cooker or hob, gas fire, and any other gas-burning appliance present. For each appliance, the engineer checks: that it is safe to operate; that the flue is in good condition and correctly expelling combustion gases; that the burner pressure is within specification; that the ventilation provision is adequate; and that all safety devices function correctly. The engineer also performs a gas tightness test on the visible pipework to confirm there are no leaks.
The CP12 does not include a boiler service. The inspection assesses whether appliances are safe — it does not clean burners, descale heat exchangers or carry out any maintenance work. A service and a CP12 inspection are two separate tasks, though many engineers offer them as a combined visit at a reduced total cost.
Who Can Issue a CP12
Only a Gas Safe registered engineer can legally issue a CP12. The engineer must be on the Gas Safe Register and must hold the appropriate competency categories covering the appliances being inspected. Any engineer who issues a CP12 certificate can be verified at GasSafeRegister.co.uk by searching their registration number. Landlords should verify the registration before booking and ask to see the engineer Gas Safe ID card on arrival at the property.
How Often Is It Required
A CP12 is required annually — every 12 months. There is no grace period. An inspection carried out on 15 November 2024 must be renewed no later than 14 November 2025. The certificate is not valid from the date of issue — it is valid for 12 months from the date of inspection. If the inspection date and the certificate issue date differ, the 12 months runs from the inspection date.
Landlord Obligations: Providing the CP12 to Tenants
Under the regulations, a landlord must: provide a copy of the current CP12 to existing tenants within 28 days of the annual inspection; provide a copy of the current CP12 to new tenants before they move into the property; keep a record of each CP12 for at least two years (or longer if the tenancy continues). Digital provision is acceptable — emailing a PDF copy to the tenant satisfies the legal requirement, though the landlord should retain proof of sending.
What Happens If a CP12 Lapses
A landlord who cannot produce a valid CP12 for a rented property is in breach of the Gas Safety Regulations. The penalty is up to £6,000 fine per offence and/or six months imprisonment. More practically, a landlord without a valid CP12 cannot legally begin a new tenancy. If a property is found to be let without a current CP12 during a local authority investigation, the landlord faces enforcement action and potential prosecution. In possession proceedings, courts have required landlords to refund rent to tenants for periods when a valid CP12 was not held.
CP12 and No Access Situations
Tenants have no obligation to allow access for the CP12 inspection on demand. The landlord must give at least 24 hours written notice before entry. If a tenant refuses access repeatedly, the landlord must demonstrate they have taken all reasonable steps to gain access — including a letter to the tenant explaining the legal requirement — before the local authority will treat an expired CP12 as a genuinely unresolvable situation. Simply allowing the certificate to lapse because a tenant refused one appointment is not a sufficient defence.