Commercial Gas Safety Certificate (CP42) — from £159.99

What is a CP42 Commercial Gas Safety Certificate?

A CP42 is the commercial equivalent of the domestic CP12 Gas Safety Certificate. It is a formal safety inspection of every gas appliance, flue, and associated pipework in a non-domestic premises, carried out by a Gas Safe registered engineer holding the relevant commercial gas competencies. The engineer checks each appliance against current gas safety standards and manufacturer specifications, then issues a written CP42 certificate for each appliance that passes the safety check.

The CP42 standard applies to a wide range of commercial gas appliances — commercial boilers and heating systems, gas-fired catering equipment (ranges, griddles, fryers, steamers, ovens), warm air heaters, gas fires in communal areas, and any other non-domestic gas appliance. Each appliance type requires a Gas Safe engineer with the relevant appliance-specific competency, which is why commercial gas safety checks cannot be carried out by engineers registered only for domestic gas work.

Our engineers hold Gas Safe registration with commercial gas and catering appliance competencies and operate across all 32 London boroughs, including the City of London. Every CP42 certificate is produced digitally and emailed to you on the same day as the inspection.

CP42 vs CP12 — what is the difference?

Both the CP12 and the CP42 are Gas Safety Certificates issued under the Gas Safety (Installation and Use) Regulations 1998, but they apply to fundamentally different types of premises and appliances.

If your property is a residential dwelling — a house, flat, or HMO — you need a CP12 Gas Safety Certificate rather than a CP42.

What does a commercial gas safety check cover?

Our Gas Safe engineers carry out a thorough, appliance-by-appliance inspection and safety check. For each gas appliance on the premises, the engineer checks:

• Visual inspection of the appliance body, casing, burners, and controls for signs of damage, deterioration, or unsafe modification
• Verification that ventilation and air supply meet current requirements for the appliance type and installation environment
• Flue integrity check — inspection of the flue, terminal, and any joints or connections for soundness and correct installation
• Combustion spillage test — checking that combustion products are safely evacuated and not spilling into the occupied space
• Gas rate measurement — verifying that the gas consumption matches the manufacturer's design specification
• Gas pressure check at the appliance inlet to confirm adequate supply pressure
• Examination of the ignition system, flame failure device, and all safety interlocks
• Tightness test of the gas pipework serving each appliance
• Classification of each appliance as safe to use, at risk (AR), or immediately dangerous (ID)

CP42 pricing

Fixed pricing by number of gas appliances. No call-out charges. A single commercial kitchen may have multiple appliances — select the count that matches your premises.

Need a domestic Gas Safety Certificate (CP12) instead? View CP12 pricing →

Comparing all certificate prices? View our complete pricing page →

What's included for £159.99

• Full safety inspection of 1 commercial gas appliance
• Ventilation and air supply verification
• Flue integrity and combustion spillage test
• Gas rate and pressure measurement
• Ignition, flame failure, and safety interlock checks
• Gas pipework tightness test
• Appliance classification (safe / at risk / immediately dangerous)
• Written CP42 certificate emailed the same day

How it works

1. 1

   Book online

   Select your appliance count, choose a date that suits your business, and pay securely. Booking takes under 3 minutes. You receive a confirmation email immediately.

2. 2

   Gas Safe engineer visits

   A Gas Safe registered engineer with commercial gas competencies arrives at the agreed time. They carry out a full safety inspection and test of every gas appliance on site. You or a nominated keyholder can provide access.

3. 3

   CP42 certificate issued same day

   Your CP42 Commercial Gas Safety Certificate is completed and emailed to you in PDF format on the same day as the inspection. Keep a copy on site and provide one to your tenant within 28 days where required by the Regulations.

CP42 — frequently asked questions

Related compliance services

Commercial premises often require a Commercial EICR alongside a CP42, and may also need a Fire Risk Assessment. For residential lets, the domestic Gas Safety Certificate (CP12) applies.