How much does a gas safety certificate cost?

Domestic gas safety certificate costs (CP12)

All domestic CP12 prices are fixed by number of gas appliances. The price you see is the price you pay — no call-out charge, no hidden fees.

What does the gas safety certificate cost cover?

A CP12 is not a simple paperwork exercise — it is a structured safety inspection of every gas appliance in the property, carried out by a Gas Safe registered engineer. Here is what the cost covers.

• Visual inspection of each gas appliance, pipework, and gas meter
• Burner pressure and gas rate test on each appliance
• Flue flow and combustion performance check (including CO spillage test on boilers)
• Safety device operation test — overheat thermostat, flame failure device
• Ventilation adequacy check for each appliance
• Gas tightness test on the pipework installation
• CP12 Landlord Gas Safety Record issued and emailed on the same day

Only a Gas Safe registered engineer can legally carry out this inspection and issue a CP12. You can verify any engineer's registration at gassaferegister.co.uk.

How our gas safety certificate costs compare

The national average for a domestic CP12 quoted by comparison sites is typically £60–£120 for a single boiler, with London prices often running higher. Prices vary significantly because many engineers quote by the hour rather than a fixed upfront price — meaning the final bill depends on how long the job takes.

Market range figures are approximate, based on published price comparison data for London and South East England (2025).

What affects the cost of a gas safety certificate?

Number of gas appliances

The primary driver. Each appliance — boiler, gas hob, gas fire, back boiler, warm air unit — must be individually tested. Prices increase in £10 bands per appliance. A property with just a combi boiler is the simplest and cheapest inspection; one with a boiler, hob and gas fire will cost more.

Boiler service

A full boiler service is not included in the standard CP12 price but can be added for a combined cost of £84.99. This includes cleaning the heat exchanger, checking the pump, pressure vessel and condensate trap, and replacing the boiler filter. Most landlords carry out both annually at the same visit.

Appliance condition and access

If an appliance is poorly maintained, difficult to access, or requires the engineer to move furniture or locate a hidden gas valve, this adds time. Our fixed price covers standard residential access — appliances should be accessible before the engineer arrives.

Whether unsafe work is found

If an appliance or section of pipework is found to be immediately dangerous, the engineer must issue a Warning Notice and may need to disconnect the appliance. Remedial work is quoted separately. A well-maintained property with annually serviced appliances is unlikely to encounter this.

Commercial vs domestic

Commercial gas safety inspections (CP42) are more complex — covering larger appliances, higher gas pressures, and commercial-grade safety devices. Commercial certificates are priced significantly higher than domestic CP12s, starting from £159.99.

Commercial gas safety certificate costs (CP42)

Commercial properties require a CP42 certificate rather than a CP12. Prices are fixed by number of gas appliances.

Need a commercial gas safety certificate? View the commercial gas safety service page →

How to keep your gas safety certificate cost as low as possible

• Count your appliances correctly before booking — only appliances supplied as part of the tenancy need testing. A tenant's own gas cooker is their responsibility.
• Book the boiler service at the same visit — the combined Gas Safety + Boiler Service at £84.99 saves money over booking separately and keeps both records aligned.
• Bundle with your EICR — our Essential Bundle (EICR + Gas Safety) costs £130 versus £144.99 separately, saving £14.99 in a single visit.
• Don't let it lapse — a missed annual renewal creates urgency and some providers charge a premium. Book one to two months before expiry.
• Ensure the engineer has clear access — all appliances, the gas meter, and the boiler flue terminal (if external) should be accessible before the appointment.
• Choose fixed pricing — an hourly rate quote is unpredictable. Fixed-price providers show the full cost before you book.

Save more — bundle your gas safety certificate

Most landlords who need a Gas Safety Certificate also need an EICR in the same year. Booking them together in one visit saves money and eliminates a second access appointment with your tenant.

See all bundle options including HMO Complete →

Compare other landlord certificate costs

Most landlords who need a Gas Safety Certificate also need an EICR and an EPC. See what each costs and compare all services on our pricing page.

Gas safety certificate cost — frequently asked questions