Gas Safe Register: How Many Engineers Are There? [2026]

Gas Safe Register is the statutory register for engineers legally entitled to carry out gas work in Great Britain, the Isle of Man, and Guernsey. Registration is mandatory — working on gas without registration is a criminal offence under the Gas Safety (Installation and Use) Regulations 1998.

As of 2025/2026:

• Approximately 115,000–120,000 individuals hold Gas Safe registration
• Approximately 45,000–50,000 businesses are registered (encompassing sole traders, partnerships, and companies)
• Total register size has declined modestly from a peak of approximately 130,000 individual engineers around 2013–2015
• Gas Safe replaced CORGI (Council for Registered Gas Installers) as the mandatory registration body in 2009

The register is maintained and enforced by Gas Safe Register Ltd, appointed by the Health and Safety Executive (HSE). All domestic, commercial, and industrial gas work in Great Britain must be carried out by a Gas Safe registered engineer.

Gas Safe engineers are not evenly distributed across the UK. Registration and concentration follows population density and the economics of the trade:

• London and South East: The highest concentration — approximately 25–30% of all registered engineers operate in this region, reflecting both population density and higher rates making self-employment more economically attractive
• North West: Second largest region by number of engineers, including Greater Manchester and Merseyside
• West Midlands: Third largest concentration, reflecting the population base
• Scotland: Approximately 10,000–12,000 registered engineers; Gas Safe covers Scotland in addition to England and Wales
• Wales and Northern Ireland: Smaller but proportionally well-served populations

For gas engineering businesses, regional concentration creates very different competitive landscapes. In inner London, there may be 2,000+ engineers operating within a 10-mile radius. In rural Yorkshire or Wales, the same 10-mile radius might contain 20–30, giving each engineer a larger captive market.

Gas Safe engineers hold different ACS (Accredited Competency Scheme) qualification categories that determine what work they're legally entitled to carry out. Common domestic categories:

• CCN1: Core domestic natural gas — the foundational qualification for domestic gas work
• CEN1: Central heating boilers (natural gas)
• CENWAT: Central heating and water heaters
• HTR1: Domestic gas fires and heating appliances
• CKR1: Domestic gas cookers and ranges
• MET1: Domestic gas meters

Commercial engineers hold additional categories (COMCAT, CCCN1 for catering, COCN1 for commercial pipework). Not all registered engineers hold all categories — a domestic gas engineer may not be qualified for commercial catering equipment, and vice versa.

When hiring or subcontracting, always verify the specific categories held by an engineer match the work they'll be doing. Gas Safe registration alone doesn't confirm qualification for specific work types.

The gas engineering workforce is aging — a trend with significant implications for the industry over the next decade:

• Estimated average age of Gas Safe engineer: 43–46 years
• An estimated 20–25% of current engineers are expected to retire within the next 10 years
• Apprenticeship completions in gas and plumbing (combined): approximately 6,000–8,000 per year, which may not fully replace retirements
• The energy transition narrative has arguably discouraged some younger people from entering the trade, creating a recruitment challenge even before the structural aging of the existing workforce

For existing gas engineering businesses, this demographic trend is positive for pricing and demand: fewer qualified engineers mean higher rates are sustainable and maintained. For the industry overall, it creates a skills gap risk if apprenticeship and retraining pipelines are not expanded.

Gas Safe Register carries out approximately 30,000–35,000 checks on registered businesses per year, including unannounced site visits to verify work standards. The register also investigates complaints from members of the public.

Unregistered gas work (illegal work) is a persistent problem. Gas Safe estimates that 1.8–2 million gas jobs are carried out illegally each year by unregistered individuals — representing a significant ongoing risk both to public safety and to legitimate businesses competing on price with those who don't bear the costs of registration.

Report illegal gas work at gassaferegister.co.uk. Convictions for illegal gas work carry fines and up to 6 months imprisonment. Legitimate gas engineers have a genuine interest in enforcement of registration requirements — illegal workers undercut prices and damage the industry's reputation.