What is a Gas Safety Certificate?

A gas safety certificate, officially called a Landlord Gas Safety Record (CP12), is a document confirming that gas appliances and installations in a property have been checked and meet safety standards. It's a legal requirement for landlords and essential for protecting tenants from carbon monoxide poisoning and gas leaks.

What is a gas safety certificate?

A gas safety certificate (CP12) is an official record proving that:

• Gas appliances have been checked and are safe to use
• Gas installations (pipework, meters, flues) meet safety standards
• Ventilation is adequate for safe appliance operation
• Safety devices are working correctly

The certificate must be issued by a Gas Safe registered engineer after carrying out specific safety checks required by law.

What does a gas safety check cover?

During a gas safety inspection, the engineer examines all gas appliances and installations:

Appliances checked

• Boilers (combi, system, and conventional)
• Gas fires and room heaters
• Cookers (ovens, hobs, ranges)
• Water heaters and immersion systems
• Warm air units
• Any other gas-powered equipment

Safety checks performed

For each appliance:

1. Operating pressure and heat input — ensuring the appliance receives the correct gas supply
2. Flue flow and combustion — checking dangerous gases are being safely expelled
3. Flame picture — confirming the flame burns correctly without risk
4. Safety devices — testing thermostats, flame supervision devices, and ventilation safeguards
5. Visual inspection — checking for corrosion, damage, and proper installation

For the installation:

• Gas meter condition and tightness
• Gas pipework integrity and support
• Ventilation adequacy for each appliance
• Flue terminations and routing
• Emergency control valve accessibility

Who needs a gas safety certificate?

Landlords (mandatory)

You must have a gas safety certificate if you're a landlord of:

• Residential rental properties
• Houses in Multiple Occupation (HMOs)
• Student accommodation
• Holiday lets and short-term rentals
• Social housing
• Staff accommodation

This applies whether you let one property or a hundred, and whether you're a private landlord, agency, or housing association.

Homeowners (recommended)

If you own and live in your own home, you're not legally required to have a gas safety certificate. However, an annual gas safety check is strongly recommended because:

• Carbon monoxide poisoning can be fatal and has no smell
• Gas leaks are dangerous and not always obvious
• Faulty appliances may be covered by warranty requirements
• A recent certificate adds value when selling your property
• It gives you peace of mind about your family's safety

Commercial premises

If you own or manage business premises with gas appliances, you have similar duties under the Health and Safety at Work Act. While the certificate format may differ slightly, the requirement for annual safety checks by Gas Safe engineers is the same.

How often do you need a gas safety certificate?

For landlords: Every 12 months. You must arrange a new inspection before the current certificate expires.

Timing tip: Many landlords schedule the check 10-11 months after the previous one, giving a buffer before expiry while still maintaining the anniversary date.

What happens during a gas safety inspection?

Before the inspection

Landlords should:

• Arrange access with the tenant
• Ensure all gas appliances are accessible
• Check the engineer is Gas Safe registered
• Keep previous certificates handy for reference

Tenants should:

• Be available or arrange access
• Move items blocking appliances
• Note serial numbers of any appliances not present during previous checks

During the inspection (typically 30-60 minutes)

The Gas Safe engineer will:

1. Check credentials — show you their Gas Safe ID card
2. Inspect each appliance — perform the safety checks described earlier
3. Test safety devices — ensure flame supervision and ventilation safeguards work
4. Examine installations — check pipework, meters, and flues
5. Document findings — record appliance details, test results, and any defects
6. Explain results — tell you immediately if anything is unsafe

After the inspection

You'll receive:

• The CP12 certificate (digital or paper)
• Warning notice(s) if any appliances are at risk or immediately dangerous
• Recommendations for repairs or improvements (if needed)

What information is on a gas safety certificate?

A valid CP12 certificate must include:

Premises details:

• Full property address
• Landlord name and address
• Tenant name (if applicable)

Engineer details:

• Gas Safe registration number
• Engineer name and signature
• Date of inspection

Appliance details (for each appliance):

• Location (e.g., "Kitchen", "Lounge")
• Type (e.g., "Boiler", "Cooker")
• Make and model
• Flue type
• Test results for operating pressure, combustion, and safety devices
• Pass/Fail/At Risk/Immediately Dangerous status

Installation checks:

• Gas tightness test result
• Gas meter and emergency control location
• Ventilation adequacy
• Overall safety status

Action required:

• Any defects found
• Remedial work needed
• Follow-up inspection requirements

Gas Safe Register - what you need to know

What is Gas Safe Register?

Gas Safe Register is the official list of gas engineers who are legally allowed to work on gas appliances in the UK. It replaced CORGI registration in 2009.

By law:

• Only Gas Safe registered engineers can work on gas appliances, fittings, and flues
• Only Gas Safe registered engineers can issue gas safety certificates
• The register is maintained by Capita Gas Registration and Ancillary Services Ltd

How to check an engineer is Gas Safe registered

Before they arrive:

1. Visit GasSafeRegister.co.uk
2. Use the "Find an Engineer" tool
3. Enter their registration number or business name
4. Check the expiry date and approved gas work categories

When they arrive:

1. Ask to see their Gas Safe ID card
2. Check the photo matches
3. Verify the expiry date (on the back)
4. Check the reverse side lists the types of gas work they're approved for

What if issues are found during the inspection?

Immediately Dangerous (ID)

If an appliance or installation poses immediate danger:

• The engineer must disconnect or turn off the gas supply immediately
• A warning notice will be attached to the appliance
• The engineer will report it to the Health and Safety Executive
• You cannot use the appliance until a Gas Safe engineer repairs and re-checks it

At Risk (AR)

If an appliance could become dangerous:

• The engineer will advise you not to use it
• They may turn it off, but won't necessarily disconnect it
• You should arrange repairs as soon as possible
• You can't legally re-let until it's repaired and re-checked

Not to Current Standards (NCS)

If something doesn't meet current standards but isn't immediately dangerous:

• You'll receive advisory notes
• The appliance can continue to be used
• You should consider upgrades when practical
• This won't prevent you issuing a certificate

Record keeping requirements

What records must you keep?

Landlords must retain:

• The current gas safety certificate
• The previous certificate (until replaced by a newer one)
• Records for at least 2 years from the date of each check

Best practice:

• Keep all certificates for the duration of the tenancy plus 2 years
• Maintain a log showing when certificates were provided to tenants
• Store copies digitally and physically
• Note any remedial work carried out

Providing certificates to tenants

New tenants:

• Must receive a copy before they move in
• Or within 28 days of the inspection (if the check is done after they move in)

Existing tenants:

• Must receive a copy within 28 days of each annual inspection
• Can be provided by hand, post, or email (if agreed)

Proof of provision:

• Keep evidence you've provided the certificate (signed receipt, email confirmation, tracked delivery)
• If a tenant refuses to accept it, keep a record of your attempts to provide it

Penalties for non-compliance

Failing to comply with gas safety regulations carries serious penalties:

Criminal prosecution

Penalties can include:

• Unlimited fines
• Up to 6 months imprisonment (summary conviction)
• Up to 2 years imprisonment (conviction on indictment)
• Prohibition from letting property

You can be prosecuted for:

• Not having an annual gas safety check
• Not providing the certificate to tenants
• Using an unregistered gas engineer
• Allowing unsafe appliances to be used

Civil penalties

Under the Housing and Planning Act 2016, local authorities can issue financial penalties:

• Up to £30,000 per offence (per property)
• No need for a criminal prosecution
• Penalties published publicly
• Appeals process available

Rent repayment orders

Tenants can apply for rent repayment orders if:

• You don't have a valid gas safety certificate
• You haven't provided them with a copy
• The property is subject to an improvement notice or prohibition order

Insurance implications

Your landlord insurance may be invalid if:

• You don't have a current gas safety certificate
• You used an unregistered engineer
• You allowed unsafe appliances to remain in use

Most insurers require evidence of annual gas safety checks as a condition of cover.

Gas safety check vs boiler service - what's the difference?

Many people confuse gas safety checks with boiler servicing. They're different:

Gas Safety Check (CP12)

Purpose: Ensure appliances are safe to use Legal status: Mandatory for landlords Frequency: Annually (for landlords) Focus: Safety checks and testing What's included:

• Combustion and flue checks
• Safety device testing
• Gas tightness testing
• Ventilation checks
• All gas appliances (not just boiler)

What's not included:

• Detailed performance diagnostics
• Component replacement (unless unsafe)
• Efficiency optimization
• Preventative maintenance

Cost: Typically £60-90

Boiler Service

Purpose: Maintain performance and prevent breakdowns Legal status: Not mandatory (but often required by warranty) Frequency: Annually recommended Focus: Maintenance and efficiency What's included:

• Clean heat exchanger and burner
• Check and replace worn parts
• Optimize settings for efficiency
• Pressure and system checks
• Preventative maintenance

What's not included:

• Official CP12 certificate
• Checks on other gas appliances

Cost: Typically £80-120

Frequently asked questions

Next steps

Not sure if you're meeting your gas safety obligations as a landlord?

Landlord Gas Safety Responsibilities →

Want to understand what happens during the inspection?

What to Expect During a Gas Safety Inspection →

Related articles:

• Landlord Gas Safety Responsibilities
• How to Find a Gas Safe Engineer
• Carbon Monoxide Safety

Useful tools:

• Responsibility Checker
• Gas Safety Self-Check