Landlord Gas Safety Certificate (CP12): What It Is and How to Get One
Quick Answer: A CP12 gas safety certificate — also called a Landlord Gas Safety Record (LGSR) — is a legal document confirming that all gas appliances, pipework, and flues in a rented property have been inspected by a Gas Safe registered engineer. UK landlords must obtain one every twelve months. Tenants must receive a copy within 28 days of the check, and new tenants must receive one before they move in.
If you rent out a property in the UK that has gas appliances, the annual gas safety check is not optional. It is a legal requirement under the Gas Safety (Installation and Use) Regulations 1998, and failing to comply carries serious consequences — including unlimited fines, potential imprisonment, and invalidation of your landlord insurance. Understanding exactly what the certificate covers, who is responsible, and what happens when access is refused puts you in a far stronger position to meet your obligations confidently.
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Key Entity Relationships
- A CP12 gas safety certificate is the informal name for a Landlord Gas Safety Record (LGSR), issued by a Gas Safe registered engineer following an annual inspection of gas appliances, pipework, and flues at a rented property.
- The Gas Safety (Installation and Use) Regulations 1998 (GSIUR) is the primary UK legislation that places a legal duty on landlords to ensure annual gas safety checks are carried out and records are maintained.
- The Gas Safe Register is the official body responsible for certifying gas engineers in the UK, replacing CORGI registration in 2009, and is the only register from which landlords should source engineers to carry out CP12 inspections.
- CORGI Proforma 12 (CP12) is the historical name for the landlord gas safety certificate, originating from the previous CORGI registration system, and the term continues to be used informally alongside Landlord Gas Safety Record.
- A Gas Safe registered engineer is the only professional legally authorised to inspect gas appliances, issue a CP12 certificate, and formally categorise an appliance as safe, at risk, or immediately dangerous.
- A boiler flue is the duct that channels combustion gases from the boiler to the outside of the building, and inaccessible flues on room-sealed fan-assisted boilers are a specific inspection challenge that requires the installation of inspection hatches in rented properties.
- An inspection hatch is an access panel installed in a ceiling or wall to provide a Gas Safe engineer with the physical access needed to inspect a concealed boiler flue during an annual gas safety check.
- The Health and Safety Executive (HSE) is the UK government body responsible for enforcing gas safety legislation, including the duties placed on landlords under the GSIUR.
- A Landlord Gas Safety Record must include the address of the property, details of each appliance inspected, the date of inspection, the engineer’s Gas Safe registration number, any defects identified, and the engineer’s signature.
- The 28-day rule requires landlords to provide existing tenants with a copy of the current gas safety record within 28 days of the annual inspection being completed.
- An “At Risk” classification is assigned by a Gas Safe engineer to a gas appliance that presents a potential safety hazard but does not require immediate isolation, and it requires remedial action before the next inspection.
- An “Immediately Dangerous” classification is assigned by a Gas Safe engineer to an appliance that presents an immediate risk to life, and the engineer will recommend its isolation and disconnection pending repair or replacement.
What is a CP12 Gas Safety Certificate?
The CP12 — formally known as the Landlord Gas Safety Record — is the document produced by a Gas Safe registered engineer after completing an annual inspection of all gas appliances, pipework, and flues at a rented property. It is the written confirmation that the property’s gas installation has been assessed and meets the safety standards required by law.
The certificate takes its informal name from CORGI Proforma 12, the document used under the CORGI registration system that preceded the Gas Safe Register. The terminology has persisted in common use even though CORGI ceased to be the registration body for gas engineers in Great Britain in 2009. Whatever it is called — CP12, LGSR, or landlord gas safety record — it refers to the same document and the same legal requirement.
A CP12 certificate is distinct from a boiler service. A service focuses on the mechanical condition and efficiency of the boiler as a unit. A CP12 inspection is a broader safety check covering all gas appliances, the gas supply pipework, and the flues, and it must be carried out regardless of whether a service has also been completed.
What a CP12 Certificate Must Include
The Gas Safety (Installation and Use) Regulations 1998 specify the information that must appear on a valid gas safety record. Any certificate that omits these details is not compliant.
| Required Detail | Notes |
|---|---|
| Address of the inspected property | Must match the rental property address |
| Date of the inspection | The date the check was carried out |
| Details of each appliance inspected | Make, model, and location where identifiable |
| Results of safety checks for each appliance | Pass, At Risk, or Immediately Dangerous |
| Any defects identified and remedial action required | Recorded for each appliance where applicable |
| Confirmation of ventilation adequacy | Checked for each appliance |
| Engineer’s full name and Gas Safe registration number | Must be verifiable on the Gas Safe Register |
| Engineer’s signature | Required for the document to be valid |
| Landlord or letting agency name and address | Identifies the responsible party |
The physical format of the certificate can vary between engineers and companies, but all of the above details must be present. Certificates should be retained for at least two years by the landlord and a copy provided to each tenant.
What the Gas Safety Check Covers
The annual inspection is more than a visual assessment. A Gas Safe engineer carries out a series of functional and safety checks across all gas appliances in the property, the supply pipework connecting them, and the flues through which combustion gases are expelled.
For each gas appliance — typically a boiler, gas hob, gas fire, or other fitted gas appliance — the engineer checks that it is operating correctly and that its location and installation remain appropriate. Ventilation channels are assessed to confirm that combustion air can reach appliances and that any required ventilation openings have not been blocked or reduced by subsequent building work or modification.
The engineer checks that combustion gases — including carbon monoxide — are being safely directed out of the property through the correct flue pathway rather than discharging into occupied spaces. Safety devices fitted to appliances, including overheat thermostats and flame failure devices, are tested to confirm they respond correctly under the conditions they are designed to address.
Following the inspection, each appliance is assigned one of three outcomes: safe for continued use, At Risk (a defect exists that requires attention but does not require immediate isolation), or Immediately Dangerous (a defect that presents an immediate risk and requires the appliance to be isolated before continued use).
Who is a Landlord for the Purpose of Gas Safety Law?
The legal definition of a landlord under the Gas Safety (Installation and Use) Regulations 1998 is broader than the term might suggest in everyday usage. Any person who rents their property to a tenant under a lease or licence of less than seven years is defined as a landlord for the purposes of the regulations and carries the full legal duty for annual gas safety checks.
This includes long-term residential tenancies, short-term lets, holiday accommodation — including cottages, chalets, caravans, and flats let for short periods — and rooms let within a larger property. It includes letting agents acting on behalf of a landlord, who share the legal responsibility for ensuring compliance when they manage the property.
A property let on a lease of seven years or more falls outside the scope of the regulation, and the tenant rather than the landlord carries responsibility for gas safety maintenance in those cases. However, the vast majority of residential rental arrangements — assured shorthold tenancies, periodic tenancies, and most short-term licences — fall well within the seven-year threshold and require full compliance.
Do Homeowners Need a CP12 Certificate?
No. Homeowners who occupy their own property are not legally required to obtain a gas safety certificate. There is no equivalent of the CP12 obligation for owner-occupiers under the Gas Safety (Installation and Use) Regulations 1998.
That said, having a Gas Safe engineer carry out an annual check of your gas appliances and pipework — and requesting a written record of the findings — is a sensible practice for any homeowner. Carbon monoxide leaks from poorly maintained boilers cause deaths in the UK every year, and the risks are not confined to rented properties. A record of annual checks also provides useful documentation if you later decide to sell or let the property, where the history of gas safety maintenance may be relevant to a buyer’s or tenant’s due diligence.
Landlord Legal Responsibilities: A Complete Overview
The legal duties placed on landlords by the Gas Safety (Installation and Use) Regulations 1998 cover four distinct areas, each of which must be met in full.
Maintenance of Gas Appliances and Pipework
Landlords must ensure that all gas appliances, flues, and pipework within their property are maintained in a safe condition and in efficient working order. This extends beyond the annual inspection — it means responding promptly to any repair or replacement need that arises between inspections, including replacement of a failing boiler when repair is no longer economical or safe. Understanding the boiler service cost breakdown is essential for landlords to budget effectively for these necessary repairs. Additionally, knowing the various factors that contribute to the total cost can help in making informed decisions when it comes to maintenance and potential upgrades. By prioritizing these expenses, landlords can prevent larger issues and maintain the safety and efficiency of their properties.
Annual Inspection by a Gas Safe Registered Engineer
The inspection must be carried out every twelve months by an engineer who holds a current Gas Safe registration that covers the specific type of work involved. Not all Gas Safe engineers are qualified to work on all appliance types — an engineer whose registration covers domestic boilers may not be qualified to inspect commercial catering equipment, for example. Verifying that the engineer’s registration covers the appliances to be inspected is the landlord’s responsibility.
Record Keeping
The gas safety record produced following each inspection must be retained for a minimum of two years. During that time it must be made available to any enforcement officer from the Health and Safety Executive upon request.
Provision of Records to Tenants
Existing tenants must receive a copy of the current gas safety record within 28 days of the inspection. New tenants must receive a copy before they move into the property — not after. If a prospective tenant requests to see the most recent gas safety record before signing a tenancy agreement, the landlord is required to provide it.
What to Do if a Tenant Refuses Access
A tenant who refuses to allow a Gas Safe engineer access to carry out the annual inspection places the landlord in a difficult legal position — but it does not remove the landlord’s duty to comply with the regulations, nor does it provide the landlord with a defence if the inspection does not take place.
The appropriate response is to document every attempt made to arrange access. Write to the tenant — by letter and by email — explaining the legal requirement, the reason for the inspection, and the date and time proposed. Keep copies of all communications. If access is repeatedly refused, seek legal advice, as a landlord cannot lawfully force entry to a tenanted property to carry out an inspection without going through the correct legal process.
The key principle is demonstrating that you have taken all reasonable steps to comply with the law. A landlord who has documented repeated attempts to arrange access is in a substantially different position to one who has made no attempt at all. The Health and Safety Executive has published guidance on this specific scenario, and consulting it — or seeking advice from a solicitor who specialises in residential landlord law — is advisable if a tenant’s refusal is sustained.
Boiler Flues and Inspection Hatches
One of the more common compliance issues in rented properties concerns boiler flues that run through walls or ceilings and are not directly accessible for inspection. Modern room-sealed fan-assisted boilers — the type most commonly installed in UK properties — have flues that channel combustion gases entirely outside the building, but the flue itself may run through a void or cavity where it cannot be seen or physically inspected without access panels.
If a Gas Safe engineer cannot access the full length of a boiler flue during an annual inspection, they are required to classify the boiler as At Risk. In more serious cases, where the configuration prevents any meaningful inspection, the engineer may issue an Immediately Dangerous classification and recommend that the boiler be isolated until access is provided. understanding back boiler mechanisms is crucial for ensuring safety and efficiency. Engineers must be familiar with the specific requirements and regulations governing these systems to prevent potential hazards. Proper knowledge and access can significantly reduce the risks associated with improper boiler operation.
The solution is the installation of inspection hatches at appropriate points along the flue route. This is work that must be carried out before the next inspection, and the cost and disruption of fitting hatches in a ceiling or wall is considerably less than the consequences of a failed inspection or a gas safety incident in an occupied property.
Landlords who are unsure whether their property’s flue arrangement requires inspection hatches should ask a Gas Safe engineer to assess the installation during or before the annual check, and should take any recommendation to install hatches seriously rather than treating it as optional.
How to Find and Verify a Gas Safe Engineer
Every gas safety inspection must be carried out by an engineer with a current Gas Safe registration that covers the type of work involved. The Gas Safe Register website — gassaferegister.co.uk — allows you to search for registered engineers by postcode and verify any individual engineer’s registration status and the categories of work they are authorised to carry out.
Every registered engineer carries a Gas Safe ID card. Asking to see this card before any work begins is not only reasonable — it is recommended practice. The card confirms the engineer’s name, their registration number, and the specific types of gas work their qualification covers. A legitimate Gas Safe engineer will always be willing to produce their card.
Be aware that Gas Safe registration must be current at the time of the inspection. Registration is renewed annually, and an engineer whose registration has lapsed is not legally authorised to carry out the inspection or issue a valid certificate, even if they were previously registered. The register website allows you to check the expiry date of any engineer’s current registration.
What Are the Implications of Carbon Monoxide Detector Issues on Obtaining a Landlord Gas Safety Certificate?
When a carbon monoxide alarm sounds unexpectedly, it indicates a potential hazard that landlords must address promptly. Failure to resolve these issues can prevent landlords from obtaining a Gas Safety Certificate, putting tenant safety at risk and possibly leading to legal repercussions. Ensuring all detectors function properly is essential.
FAQ
What is a CP12 gas safety certificate?
A CP12 gas safety certificate — formally known as a Landlord Gas Safety Record — is the legal document produced by a Gas Safe registered engineer following an annual inspection of gas appliances, pipework, and flues at a rented property. It records the details of each appliance inspected, the outcome of the safety checks, any defects identified, and the engineer’s Gas Safe registration number. Landlords in the UK are legally required to obtain one every twelve months under the Gas Safety (Installation and Use) Regulations 1998.
How often does a landlord need a gas safety certificate?
A gas safety certificate must be obtained every twelve months. The inspection must be carried out by a Gas Safe registered engineer, and the resulting record must be retained by the landlord for at least two years. A copy must be provided to existing tenants within 28 days of the inspection and to new tenants before they move in. There is no flexibility in the twelve-month frequency — the duty applies regardless of when the last inspection was conducted or whether any faults were found.
What happens if a landlord doesn’t have a gas safety certificate?
Failure to obtain a valid annual gas safety certificate is a criminal offence under the Gas Safety (Installation and Use) Regulations 1998, enforced by the Health and Safety Executive. Penalties include unlimited fines and up to two years’ imprisonment in serious cases. In addition, operating without a valid certificate typically invalidates landlord insurance, may affect the validity of the tenancy agreement, and can prevent a landlord from serving a Section 21 notice to regain possession of the property in England.
Do homeowners need a CP12 certificate?
No. The legal requirement for an annual gas safety certificate applies only to landlords renting out property under a lease or licence of less than seven years. Owner-occupiers are not required by law to obtain a gas safety record. However, having a Gas Safe engineer carry out annual checks and providing a written record of findings is strongly advisable for any home with gas appliances, both for safety reasons and as useful documentation if the property is later sold or let.
What does a gas safety check cover?
A gas safety check covers all gas appliances fitted in the property — typically the boiler, gas hob, and any gas fires — along with the supply pipework and flues. The engineer checks that each appliance is operating correctly, that ventilation is adequate, that combustion gases are being safely expelled through the flue, and that all safety devices function as intended. Each appliance is classified as safe, At Risk, or Immediately Dangerous based on the findings, and any defects are recorded on the certificate.
What is an inspection hatch and why do I need one?
An inspection hatch is an access panel installed in a wall or ceiling to allow a Gas Safe engineer to physically inspect a section of boiler flue that would otherwise be concealed and inaccessible. Room-sealed fan-assisted boilers have flues that often run through building voids, and if these cannot be accessed for inspection, the engineer must classify the boiler as At Risk or Immediately Dangerous. Landlords are required to ensure flues are accessible for inspection, making the installation of hatches where necessary a legal compliance issue rather than an optional upgrade.
Can a tenant refuse the annual gas safety inspection?
A tenant can refuse access, but this does not remove the landlord’s legal duty to ensure the inspection takes place. If a tenant refuses access, the landlord must document every attempt to arrange the inspection in writing, keep copies of all correspondence, and continue to make reasonable efforts. The Health and Safety Executive has issued guidance on this specific scenario. If a tenant’s refusal is sustained, the landlord should seek legal advice — but the key principle is demonstrating that all reasonable steps to comply with the law have been taken and documented throughout.
How do I verify that a gas engineer is Gas Safe registered?
You can verify any engineer’s registration on the Gas Safe Register website at gassaferegister.co.uk, which allows you to search by name or registration number and confirms the categories of work the engineer is authorised to carry out. You should also ask the engineer to show their Gas Safe ID card before work begins. The card confirms their registration number, the types of gas work they are qualified to undertake, and the expiry date of their current registration. An engineer whose registration has lapsed cannot legally carry out a CP12 inspection or issue a valid certificate.
Conclusion
A CP12 gas safety certificate is not a box-ticking exercise — it is the primary mechanism through which UK landlords demonstrate that their tenants are living in a property where the gas installation has been independently assessed as safe. The legal framework around it is clear, the penalties for non-compliance are serious, and the practical steps required to meet the obligation are straightforward.
Arranging an annual inspection with a Gas Safe registered engineer, retaining the certificate for at least two years, and providing copies to tenants within the required timeframes covers the core of the legal duty. Staying alert to issues around flue accessibility, ensuring inspection hatches are fitted where needed, and documenting all communications with tenants who are slow to arrange access round out the compliance picture.
If you are unsure about any aspect of your gas safety obligations as a landlord, the Health and Safety Executive publishes detailed guidance at hse.gov.uk, and a Gas Safe registered engineer will be able to advise on any property-specific questions during the annual inspection.
