A CP17 is the form most gas engineers use to record a safety inspection of a commercial gas installation. Its full name is the Gas Installation Safety Report (Non Domestic), and CP17 is the code CORGIdirect gives it. It covers the meter, the installation pipework and its tightness test, and each appliance with its flue, ventilation and safety devices.
If you can smell gas now: call the National Gas Emergency Service on 0800 111 999 in England, Scotland or Wales, or the Northern Ireland Gas Emergency Service on 0800 002 001. Both are free and open 24 hours a day.
No law names the CP17. This guide sets out what the law does require of a business, where the yearly check comes from, and when a building with a flat in it needs a landlord's CP12 as well. It covers Great Britain, with a note on Northern Ireland at the end.
Is a CP17 a legal requirement?
Not by name, and not on a fixed date. Two regulations matter.
Regulation 36 of the Gas Safety (Installation and Use) Regulations 1998 is the landlord's duty: a safety check every 12 months and a record for the tenant. It does not cover gas used only in a business. The regulation excludes "any gas appliance or installation pipework exclusively used in a part of premises occupied for non-residential purposes".
Regulation 35 is the duty that applies to a business. Every employer and self-employed person must make sure that any gas appliance, installation pipework or flue at a place of work they control "is maintained in a safe condition so as to prevent risk of injury to any person". It sets no interval and asks for no particular form.
HSE's code of practice, L56, says what that maintenance should include as a minimum where the manufacturer gives no instructions: an examination of the appliances, pipework, ventilation and flue for deterioration, performance tests, and the remedial work needed. A CP17 is a written record of exactly that, which is why a business is asked for one.
How often?
Follow the manufacturer's instructions first. For catering, HSE's guidance sheet CAIS23 says "annual inspections are a reasonable minimum frequency", with repairs as necessary. The same sheet says its guidance is not compulsory, but that following it will normally be enough to comply with the law.
So the yearly check is HSE's general rule, not a date in the regulations. A business that goes longer has to be able to show its gas is still maintained in a safe condition.
Shops with a flat above, pubs, hotels and B&Bs
This is where the two duties meet. Regulation 36 covers any appliance or pipework that "directly or indirectly" serves a home that is let, even if it sits in the commercial part of the building. A boiler in a shop that also heats the flat upstairs is a landlord's appliance for the flat.
HSE answers the question directly: if you own a shop and rent out the flat above, "domestic gas duties apply to the flat, so you must arrange an annual gas safety check." In hotels and B&Bs, appliances serving guest accommodation must be checked every year as well.
In practice a building like this can need two records: a landlord gas safety record (CP12) for everything that serves the flat, and a CP17 for the gas used only by the business.
Where a pub, shop or office is leased, the tenant business has the regulation 35 duty, and the landlord may have duties too. HSE's code of practice recommends that the two agree in the lease who looks after what, so nothing falls between them.
Who can carry it out
Any work on a gas fitting in a shop, restaurant, school, hospital or office must be done by a Gas Safe registered engineer who is qualified for that work. HSE puts it plainly: "It's illegal for anyone else to do it. It's your responsibility to check a person is registered and is qualified."
An engineer's Gas Safe ID card lists what they are qualified for. Commercial work has its own categories, such as commercial pipework, commercial catering and commercial laundry. Ask to see the card and check it covers the appliances on site.
This is not a paperwork point. In 2019 an engineer who was not registered for the work carried out a commercial gas safety check at a takeaway in Teignmouth, using his employer's Gas Safe number on the paperwork. A council officer later found irregularities. Registered engineers who went back found gas escapes classed as Immediately Dangerous. He received 10 months in prison for each offence, suspended for 12 months (reported by Gas Safe Register's magazine, Registered Gas Engineer, March 2021).
Where the gas regulations do not apply
The 1998 regulations do not apply at some workplaces, including mines, quarries, factories, agricultural premises, temporary installations on construction sites and sewage works. There, the general duties of the Health and Safety at Work etc Act 1974 apply and the work must be done by a competent person, who does not have to be Gas Safe registered. Any part of those premises used to live or sleep in is still covered by the gas regulations.
What a CP17 records
The current CORGIdirect form records, for each appliance, its details, operating pressure or heat input, flue gas analyser readings, safety devices, ventilation and the condition and operation of the chimney or flue. For the installation it records the meter, the pipework and whether a strength or tightness test was done, plus any remedial work, warning notices and the engineer's sign-off. The revised form fits four appliances to a sheet.
The inspection itself is carried out to the industry standards for the installation in front of you. The main ones are:
| Standard | Current edition | What it covers |
|---|---|---|
| IGE/UP/1 | Edition 2, amended 2005 | Strength testing, tightness testing and direct purging of industrial and commercial installations |
| IGE/UP/1A | Edition 2, amended 2005 | The same for small low-pressure natural gas installations |
| IGEM/UP/1B | Edition 4, in effect from 1 October 2026 | Tightness testing and purging of small installations, including small non-domestic premises |
| IGEM/UP/2 | Edition 4, July 2025 | Installation pipework on industrial and commercial premises |
| IGEM/UP/10 | Edition 4, amended 2017 | Flued appliances in industrial and commercial premises |
| BS 6644:2011 | Current, under review | Gas hot water boilers from 70 kW to 1.8 MW |
| BS 6173:2020 | Current | Installing and servicing gas catering appliances |
| IGEM/UP/19 | Edition 2, July 2022, with Supplement 1, August 2024 | Interlocks and air quality in commercial catering |
| IGEM/G/11 | Edition 2, amended July 2025 | The Gas Industry Unsafe Situations Procedure |
These standards are sold by IGEM and BSI. Test pressures, durations and limits come from the current edition, so they are not repeated here.
When something is unsafe
An engineer who finds an appliance they suspect is dangerous must tell the responsible person, which can be the occupier or the owner. HSE's code of practice says this should be in writing. The engineer has no legal power to disconnect it without consent, but the responsible person must not use the appliance, or let anyone else use it, while they know or suspect it is dangerous. Engineers classify what they find using the Gas Industry Unsafe Situations Procedure.
Commercial kitchens: the CP42
Catering has its own form, the CP42. Where a kitchen has mechanical ventilation, HSE's catering guidance says the installer should have fitted an interlock, so that if the ventilation fails the gas supply to the appliances shuts off. Manual bypasses of these interlocks are not permitted. For older kitchens with no interlock, HSE says to assess whether a risk is likely to arise and, if so, prevent or control it.
Whether a kitchen counts as commercial is not always obvious. In an April 2024 DIYnot thread, the person running a village hall said their service company first treated the hall's kitchen as commercial, asking about an interlock, and then decided it was not. Two replies called it "a grey area" and suggested asking Gas Safe Register for a ruling. If you are unsure, ask them and keep the answer in writing.
The CP forms side by side
| Form | Name | Used for |
|---|---|---|
| CP12 | Landlord Gas Safety Record | Homes that are let, under regulation 36 |
| CP15 | Plant Commissioning / Servicing Record (Non Domestic) | Commissioning or servicing one piece of plant |
| CP16 | Gas Testing and Purging Form (Non Domestic) | Strength and tightness tests and purging |
| CP17 | Gas Installation Safety Report (Non Domestic) | Inspecting a whole commercial installation |
| CP42 | Gas Safety Inspection Form | Commercial catering appliances |
| CP44 | Mobile Catering Vehicle / Trailer Safety Check | Food vans and trailers |
Northern Ireland
Northern Ireland has its own Gas Safety (Installation and Use) Regulations (Northern Ireland) 2004. Its regulation 35, the duty on employers and the self-employed, is worded the same as in Great Britain. Amendments coming into force on 30 November 2026 bring in changes Great Britain made in 2018, including letting landlords have the check done up to two months early, but they do not change the duty on businesses.
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Frequently asked questions
Is a CP17 the same as a CP12?
No. A CP12 is the landlord's record for homes that are let, required every 12 months by regulation 36. A CP17 records an inspection of gas used by a business.
Does my shop need a gas safety certificate by law?
The law requires the gas in your shop to be maintained in a safe condition by a qualified Gas Safe registered engineer. It does not name a certificate. A CP17 is the usual written proof that the inspection was done. If you let a flat in the same building, that flat needs a landlord gas safety record every year.
How long is a CP17 valid?
It has no legal expiry date. For catering, HSE treats yearly inspection as a reasonable minimum. Otherwise, follow the manufacturer's instructions for each appliance.
Can a domestic gas engineer do a CP17?
Only if their Gas Safe registration includes the commercial categories for the appliances and pipework on site. Check their ID card.
Sources
Checked against these on 2026-10-29.
- Gas Safety (Installation and Use) Regulations 1998, regulation 35 (duties of employers and self-employed persons)
- Gas Safety (Installation and Use) Regulations 1998, regulation 36 (duties of landlords)
- Gas Safety (Installation and Use) Regulations 1998, regulation 2 (interpretation and application)
- Gas Safety (Installation and Use) Regulations 1998, regulation 3 (qualification and supervision)
- Gas Safety (Installation and Use) Regulations 1998, regulation 34 (use of appliances)
- HSE L56, Safety in the installation and use of gas systems and appliances, fifth edition (2018)
- HSE: Gas safety, employers and businesses (updated 1 March 2021)
- HSE CAIS23, Gas safety in catering and hospitality (rev3, 2017)
- HSE: Landlords, who is responsible for gas safety checks (page dated 23 September 2024)
- Gas Safe Register: commercial ID card work categories
- CORGIdirect: Non Domestic Gas Forms
- CORGIdirect: Gas Installation Safety Report (Non Domestic) CP17
- IGEM standards pages (IGE/UP/1, IGE/UP/1A, IGEM/UP/1B Edition 4, IGEM/UP/2 Edition 4, IGEM/UP/10, IGEM/UP/19, IGEM/G/11)
- BSI Knowledge: BS 6173:2020, BS 6644:2011
- Registered Gas Engineer (Gas Safe Register), 31 March 2021: Engineer faked employer's details on kebab shop certificate
- DIYnot forum thread, April 2024: When is a gas oven a commercial appliance?
- Gas Safety (Installation and Use) (Amendment) Regulations (Northern Ireland) 2026, S.R. 2026/178
- Gas Safety (Installation and Use) Regulations (Northern Ireland) 2004
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Corrected and updated 2026-10-29. This article is for general guidance only and does not constitute legal or professional advice. Always refer to the relevant standards and consult qualified professionals for definitive requirements.