Gas Safe Registered · London & M25 · Annual Requirement

Gas Safety Certificate (CP12) from £49.99

Annual CP12 landlord gas safety inspection, a legal requirement under the Gas Safety (Installation and Use) Regulations 1998. Gas Safe Registered engineers, no hidden charges, certificate emailed within 24 hours.

Next-day appointments available across London and the M25 area. Most inspections confirmed within 1–3 days.

from£49.99

Book my CP12, from £49.99See full pricing
From
£49.99
Required
every 12 months
Appointments
next-day available
Certificate
emailed within 24 hours
Accreditation
Gas Safe Registered

What is a Gas Safety Certificate (CP12)?

A Gas Safety Certificate, formally known as a CP12, is a document confirming that all gas appliances, flues and pipework in a rental property have been inspected by a Gas Safe Registered engineer and found to be safe. The engineer checks each appliance for correct operation, adequate ventilation, secure flue connections and correct gas pressure. Every appliance inspected is listed on the certificate along with its result.

The name CP12 comes from the standard inspection form used by Gas Safe engineers. It is not the same as a boiler service, a CP12 tests whether appliances are safe, while a service checks performance and efficiency. If you want both, we offer a combined gas safety check and boiler service in a single visit.

For landlords in the private rented sector, a valid CP12 is one of the most critical compliance documents you hold. Gas appliances that are not regularly inspected can develop faults that lead to carbon monoxide poisoning, a serious and potentially fatal risk. The annual inspection is your primary defence against that risk, and the CP12 is the evidence that you have met your legal duty of care.

Legal requirement: The Gas Safety (Installation and Use) Regulations 1998 require landlords to arrange an annual gas safety check by a Gas Safe Registered engineer, provide the signed CP12 to tenants, and keep records for at least 2 years. Failure to comply is a criminal offence carrying an unlimited fine and up to 2 years' imprisonment.

Gas safety legal requirements for landlords

The Gas Safety (Installation and Use) Regulations 1998 place specific obligations on every landlord who provides gas appliances in a rental property. The regulations apply to all privately rented properties, assured shorthold tenancies, periodic tenancies, HMO licences, houses in multiple occupation and student lets alike. There is no minimum tenancy length: even short-term lets require a valid CP12.

The gas safety check must be carried out by an engineer who is registered on the Gas Safe Register. It is a criminal offence to carry out gas work , including safety inspections, without Gas Safe registration. Landlords have no discretion on this point: only a Gas Safe Registered engineer can sign and issue a valid CP12 certificate.

As a landlord you must:

  • ✓Arrange an annual gas safety check by a Gas Safe Registered engineer
  • ✓Provide a copy of the CP12 to existing tenants within 28 days of the inspection
  • ✓Provide a copy to new tenants before they move in (not within 28 days, before)
  • ✓Keep a record of every gas safety check for at least 2 years
  • ✓Ensure access is available for the engineer, document failed access attempts in writing
  • ✓Not allow tenants to use an appliance that has been condemned by the engineer

The regulations apply to England, Wales and Scotland. Northern Ireland has separate gas safety legislation, if your rental property is in Northern Ireland, check with the relevant local authority.

Gas Safety Certificate pricing

Fixed pricing per number of gas appliances. The price you see is the price you pay, no call-out charges, no hidden fees. Most domestic rental properties have 1 gas appliance (the boiler), priced at £49.99. Properties with a boiler, hob and gas fire cost £69.99 for all three.

Gas Safety Certificate (CP12), price by appliance count

1 Gas Appliance (CP12)Most popular£49.99
2 Gas Appliances (CP12)£59.99
3 Gas Appliances (CP12)£69.99
Gas Safety + Boiler Service (CP12)£84.99

Additional charges (where applicable)

  • Parking charge if no free on-site parking is available: £10
  • Properties in the London Congestion Charge Zone: £20

Want a detailed breakdown of Gas Safety Certificate costs? See our full Gas Safety pricing guide →

Need a commercial gas safety certificate for a business premises? See commercial CP42 pricing →

Comparing all landlord certificate prices? View our complete pricing page →

Booking a CP12 alongside an EICR certificate? Combine both in a single engineer visit with our landlord certificates bundle →

What's included for £49.99

Every CP12 inspection covers all required safety checks for each gas appliance included in the tenancy, at no extra cost beyond the price shown.

  • Inspection of all gas appliances included in the tenancy (boiler, hob, gas fire)
  • Flue integrity and terminal position check for each appliance
  • Ventilation adequacy check, ensuring correct air supply for combustion
  • Gas pressure and flow rate tests at every appliance
  • Safety device checks, thermostats, flame failure devices, overheat cut-outs
  • Gas tightness test on accessible pipework
  • Signed CP12 certificate listing every appliance and its result
  • Certificate emailed within 24 hours, ready to forward to your tenant

What the Gas Safe engineer checks

A CP12 inspection is more thorough than a visual check. The engineer works to a defined checklist for each appliance and records the result of every test on the certificate.

Boiler

  • Flue integrity and terminal clearances
  • Combustion analysis and CO reading
  • Heat exchanger condition
  • Safety devices, overheat stat, pressure relief
  • Gas pressure at burner

Gas hob and cooker

  • Burner operation and ignition
  • Flame stability and colour
  • Flame failure device function
  • Gas pressure at burner
  • Adequate ventilation for the kitchen

Gas fire and other appliances

  • Flue draw and integrity
  • Pilot light and main burner stability
  • Safety device checks
  • Ventilation adequacy
  • Gas pressure and flow

Gas pipework

  • Gas tightness test on accessible pipework
  • Pipe routing and supports
  • Meter condition and isolation valve
  • No signs of corrosion or damage
  • Emergency control valve accessible
Carbon monoxide risk: Faulty gas appliances are the primary cause of CO poisoning in rental properties. The annual CP12 inspection is the most effective way to detect combustion problems before they become dangerous. We strongly recommend fitting a CO alarm in every room with a gas appliance, this is a legal requirement in Scotland and mandatory for new tenancies in England from October 2022.

How to book your landlord gas safety certificate

Booking a CP12 takes under 3 minutes. Next-day appointments available across all 33 London boroughs and the wider M25 area.

  1. 01

    Book online

    Choose your appliance count, pick a date and pay securely online. Next-day slots available across London and the M25 area, no phone calls required. You'll receive a booking confirmation immediately.

  2. 02

    Gas Safe engineer visits

    A Gas Safe Registered engineer arrives at your agreed time and carries out the full CP12 inspection. You don't need to be present, a tenant, keyholder or letting agent can provide access. The inspection typically takes 30–90 minutes.

  3. 03

    Certificate emailed within 24 hours

    Your signed CP12 gas safety certificate is emailed to you on the day of the inspection, usually within a few hours of the engineer completing. Forward it to your tenant straight away to meet your 28-day obligation.

We cover all 33 London boroughs and the wider M25 area. Check if we cover your area →

Why Gas Safe registration matters

The Gas Safe Register is the official list of gas engineers legally qualified to work on gas appliances in Great Britain. Appointed by the Health and Safety Executive (HSE), it replaced CORGI in April 2009. Every engineer on the register carries a Gas Safe ID card showing their name, registration number and the specific appliance types they are qualified to work on.

It is a criminal offence for any person who is not Gas Safe registered to carry out gas work, including safety inspections. A CP12 signed by an unregistered engineer is not legally valid, and a landlord relying on such a certificate remains in breach of the Gas Safety (Installation and Use) Regulations 1998. Every engineer who carries out our CP12 inspections is Gas Safe registered, you can verify their credentials on the Gas Safe Register engineer search.

When you book through My Landlord Certificate, your engineer's registration number appears on the CP12 certificate itself. Your letting agent, mortgage lender or local authority can verify the registration at any time, giving you an auditable, legally watertight record of compliance.

Within 24 hours

Certificate delivery

emailed after inspection

12 months

CP12 validity

annual renewal required

See what landlords say about our gas safety service on our reviews page →

What each CP12 test actually involves

A CP12 is not a quick visual check. For every gas appliance in the property, boiler, gas fire, hob, water heater, the engineer runs a series of specific measurements. Here is what each check involves and why it matters.

Gas rate+
The engineer measures how quickly each appliance is consuming gas using the gas meter. This confirms the appliance is burning at the designed rate, too high or too low indicates a fault with the gas valve or burner.
Working gas pressure+
Measured at the appliance inlet. Incorrect pressure indicates a problem with the gas regulator or network supply, and can cause poor combustion or accelerated appliance wear.
Flue gas analysis (combustion analysis)+
The engineer inserts a calibrated probe into the flue and measures CO₂ and CO (carbon monoxide) levels in the exhaust gases. This is the most critical test. A high CO reading means the appliance is burning incompletely, a potentially fatal finding that results in the appliance being declared unsafe and taken out of service.
Flue integrity and spillage test+
Confirms that combustion gases are travelling up the flue and venting outside, not spilling back into the room. For open-flued appliances such as older gas fires and back boilers, a smoke pencil test near the air inlet confirms the draught is working correctly.
Ventilation adequacy+
The engineer checks there is sufficient air supply for combustion. Sealed rooms, blocked air bricks, and draught exclusion can restrict airflow and cause incomplete combustion, which produces carbon monoxide.
Safety device testing+
Flame failure devices (which cut off gas if the flame goes out), overheat thermostats, and pressure relief valves are each tested to confirm they activate correctly. A safety device that does not trip is typically a fail.
Visible pipework inspection+
All accessible gas pipework is examined for corrosion, physical damage, and correct mechanical support. The engineer also checks the meter and emergency control valve are accessible and in working order.

Carbon monoxide, why the annual check matters

Carbon monoxide (CO) is produced when gas appliances burn incompletely. It is colourless, odourless, and tasteless, completely undetectable by human senses. It binds to haemoglobin in the blood, preventing oxygen from reaching cells. At low concentrations it causes headaches, nausea and dizziness. At higher concentrations it causes loss of consciousness and death.

Around 50 people die from accidental CO poisoning in the UK every year, and over 4,000 are treated in A&E. The majority of cases involve gas appliances, boilers, gas fires, and back boilers in poorly maintained or poorly ventilated properties.

The annual CP12 is your primary defence. A flue gas analysis during every annual check identifies developing combustion problems long before CO levels in the room become dangerous.

CO alarm, legal requirement: Since October 2022, landlords in England are legally required to fit a carbon monoxide alarm in every room containing a fixed combustion appliance, including rooms with boilers and gas fires. The alarm must be in working order at the start of every new tenancy. Failure to comply carries a fine of up to £5,000. A CO alarm is not a substitute for the annual gas safety check. It is a last-resort warning device, not a replacement for the preventive inspection that catches problems before they release CO into your tenants' home.

How to read a CP12 Gas Safety Certificate

A CP12 is typically one or two pages. Here is what each section contains and what to look for when you receive yours.

✓

Property and landlord details

Confirms the correct address and your name as the landlord. Check these match your tenancy agreement exactly.

✓

Engineer details

Full name, Gas Safe registration number, and employer. You can, and should, verify this number at gassaferegister.co.uk before work begins.

✓

Appliance table

One row per appliance showing the type (e.g. 'Worcester Bosch 30i combi boiler'), its location in the property, and the inspection date.

✓

Results columns

For each appliance: Gas rate (Pass/Fail), Gas pressure (Pass/Fail), Combustion analysis CO/CO₂ (recorded values), Flue test (Pass/Fail), Safety devices (Pass/Fail), and an overall appliance result of PASS or UNSAFE.

✓

Defects section

If any appliance is declared unsafe, the defect is described and the action taken is recorded, for example: 'Appliance isolated at inlet valve, Do Not Use until repaired'. An unsafe appliance will also have a red warning sticker attached to it.

✓

Next service due

12 months from the inspection date. Diarise this immediately. A compliance gap, even a single day, is a breach of the regulations. Book before the expiry date, not after.

We email your CP12 as a PDF within 24 hours of the inspection. It is formatted to match exactly what local authorities and letting agents expect to see. Forward it to your tenant straight away.

Gas Safety Certificate, frequently asked questions

More questions about gas safety for landlords? See our full FAQ →

Ready to book your Gas Safety Certificate?

Book online in under 3 minutes. A Gas Safe Registered engineer will confirm your appointment. CP12 certificate emailed within 24 hours.

Next-day appointments available across London and the M25 area, or call for priority slots.

Book my CP12, from £49.99

No hidden charges. Gas Safe Registered. Certificate emailed within 24 hours.