A Gas Safety Certificate, formally known as a CP12, is one of the most fundamental legal obligations a private landlord in England has. It must be renewed every 12 months, carried out by a Gas Safe registered engineer, and a copy must be given to every tenant. Failure to comply is not just a civil matter, it is a criminal offence under the Gas Safety (Installation and Use) Regulations 1998. This article sets out exactly what the law requires, what the certificate must contain, and what the consequences are for landlords who miss the renewal deadline.
What law requires a Gas Safety Certificate?
The obligation to carry out annual gas safety checks is set out in Regulation 36 of the Gas Safety (Installation and Use) Regulations 1998. The regulation imposes two main duties on landlords: a duty to maintain gas appliances and flues in a safe condition, and a duty to arrange an annual safety check. These are separate and distinct obligations. (Source: Gas Safety (Installation and Use) Regulations 1998, Regulation 36; HSE guidance on landlord gas safety duties.)
The Regulations apply to all gas appliances and flues provided by the landlord in a rental property. They do not apply to appliances owned by the tenant.
Who can carry out a gas safety check?
The annual gas safety check must be carried out by, or by an employee of, a member of a class of persons approved by the Health and Safety Executive for this purpose. In practice this means a Gas Safe registered engineer. A landlord must not use an unregistered engineer to carry out a gas safety check, doing so means the check has no legal validity and the landlord remains in breach of the Regulations. (Source: Gas Safety (Installation and Use) Regulations 1998, Regulation 36(4); HSE guidance.)
Landlords can verify whether an engineer is Gas Safe registered by checking the Gas Safe Register at gassaferegister.co.uk.
How often must the check be carried out?
The check must be carried out within 12 months of the appliance or flue being installed, and at intervals of not more than 12 months thereafter. For new tenancies, the check must have been carried out within 12 months before the tenancy begins, or within 12 months of the appliance being installed — whichever is later. (Source: Gas Safety (Installation and Use) Regulations 1998, Regulation 36(3).)
What must the Gas Safety Certificate record?
The record of the gas safety check — the CP12 — must contain the following information: the date on which the appliance or flue was checked; the address of the premises; the name and address of the landlord or their agent; a description and location of each appliance or flue checked; any safety defect identified; any remedial action taken; confirmation that the check complies with the requirements of the Regulations; the name and signature of the individual carrying out the check; and the registration number with which that individual or their employer is registered with the Gas Safe Register. (Source: Gas Safety (Installation and Use) Regulations 1998, Regulation 36(3)(c); HSE guidance.)
A safety check record must not be issued until all required tests and examinations have been completed on all relevant appliances and flues.
What must a landlord do with the certificate?
Once the gas safety check has been carried out and the record produced, the landlord must give a copy to each existing tenant within 28 days of the check date. For new tenants, a copy of the most recent certificate must be given before they occupy the property. Where a tenant's right to occupy is for a period not exceeding 28 days, a copy of the record may instead be prominently displayed within the property. (Source: Gas Safety (Installation and Use) Regulations 1998, Regulation 36(6).)
The landlord must also retain a copy of every gas safety record until two further checks have been carried out — effectively keeping records for at least two years. (Source: Gas Safety (Installation and Use) Regulations 1998, Regulation 36(3)(c).)
What happens if a safety defect is found?
Where a gas safety check reveals a safety defect, the landlord must take prompt action to correct it. A landlord should not allow a tenant to continue using an appliance shown to be unsafe on the safety check record. Where an engineer discovers an unsafe appliance, the user and owner — in rented accommodation, the landlord — must be informed in writing that the appliance is unsafe and that continued use is an offence. (Source: HSE guidance on gas safety for landlords.)
What are the penalties for non-compliance?
Failing to comply with the duties under Regulation 36 is a criminal offence. The Health and Safety Executive is the enforcing authority. A landlord convicted of an offence under the Gas Safety Regulations is liable to a fine. The Regulations also provide a defence of reasonable steps — a landlord is not guilty of an offence if they can show they took all reasonable steps to prevent the contravention. However, this defence is interpreted strictly and must be demonstrated with evidence. (Source: Gas Safety (Installation and Use) Regulations 1998, Regulation 39; HSE guidance.)
In addition to criminal liability, a gas safety failure can have serious consequences for a landlord's position in possession proceedings. Under the Renters' Rights Act 2025, courts will scrutinise a landlord's compliance history. A landlord who cannot demonstrate a current Gas Safety Certificate is in a weaker position in any dispute or possession claim.
What about properties with no gas supply?
Where a rental property has no gas supply and no gas appliances, Regulation 36 does not apply and no Gas Safety Certificate is required. A landlord should nonetheless keep a clear record that the property has no gas, particularly where a previous tenant may have had a gas appliance removed. This avoids any ambiguity about why no certificate exists for the property.
What this means for landlords
The 12-month renewal deadline is absolute. There is no grace period. A Gas Safety Certificate that has expired means the landlord is in breach of the Regulations for every day the property is let without a valid check.
The certificate must be given to tenants — obtaining it is not enough. A landlord who has a valid CP12 but has not provided a copy to the tenant within 28 days of the check is also in breach of a separate duty under Regulation 36.
Only a Gas Safe registered engineer can carry out the check. A check carried out by an unregistered person has no legal effect.
Records must be kept for a minimum of two years. A landlord who cannot produce their last two gas safety records, including the most recent one, is not in a position to demonstrate compliance if challenged.
This article is for informational purposes only and does not constitute legal advice.