Written for plumbers, gas and heating engineers, electricians, heat pump and drainage firms, bathroom installers doing their own plumbing, and small multi-trade firms serving landlords, anywhere in the UK.
The short version
- Match every job to the engineer's card.Check their Gas Safe categories or scheme on the day, before each type of job. A gas job outside their categories counts as unregistered work.
- Certify only work you did or supervised.For anyone else's work, inspect and report, promise no certificate, and leave regularisation to the council.
- Notify notifiable work within 30 days.In England, new or replacement gas boilers go through Gas Safe, and notifiable electrical work through your self-certification scheme (As of Oct 2026).
In this trade the law decides who may touch the work, not just how well it is done. A gas job done outside an engineer's categories counts as unregistered work. A new boiler that was never notified surfaces later, when the house is sold. Build the checks into booking, not into the van.
Gas
Every business working on gas for gain must be on the Gas Safe Register
Each engineer holds categories, such as CCN1 for core domestic, CENWAT for boilers and water heaters, CKR1 for cookers and HTR1 for fires, assessed through ACS every 5 years, and the business renews yearly. Commercial and LPG work need their own categories. Working outside your categories is working unregistered, and a trainee works only under the direct supervision of a registered engineer holding the category. Breach is an offence carrying an unlimited fine or up to 2 years' imprisonment on indictment. As of Oct 2026.
Gas Safety (Installation and Use) Regulations 1998 (SI 1998/2451) reg 3; Health and Safety at Work etc. Act 1974 s.33
Electrical
Notifiable electrical work in an English home
Notifiable work needs a person registered for that work with a current authorised self-certification scheme, who self-certifies it within 30 days of completion, or a building notice to building control, with the council's fee, before work starts. The government's 17 September 2026 list names BESCA, Blue Flame Certification, Certsure trading as NICEIC, NAPIT and OFTEC. Non-notifiable work still has to comply and gets a certificate. Wales kept a wider notifiable list, and Scotland works through the building warrant. As of Oct 2026.
Building Regulations 2010 Part P, reg 12(6A)
As of Oct 2026, BS 7671 Amendment 3 is withdrawn from 15 October 2026: design and certify new work to Amendment 4 from that date, and say so on the certificate.
Water, hot water and heat pumps
As of Oct 2026, unvented hot water storage over 15 litres needs a G3-qualified installer and is notified. In England and Wales, some water fittings need advance notice to the water company, such as a bath over 230 litres or a pump drawing over 12 litres a minute; consent is treated as given if not refused within 10 working days. An approved contractor under WIAPS or a WaterSafe scheme skips some notices and certifies the work. For heat pumps, use current MCS certification, and hold F-gas personal and company certificates before breaking into a refrigerant circuit (sealed monobloc installs need neither).
Notifying the job
Notify within 30 days, or the problem waits for the sale
In England and Wales, a new or replacement gas boiler, fire or warm air unit is notifiable. A Gas Safe business notifies it through Gas Safe within 30 days of completion, and the householder gets a compliance certificate. A missed notification is fixed by a late notification while the scheme accepts it, or a council regularisation application. Building control can now enforce for 10 years after completion (in England from 1 October 2023, in Wales from 1 July 2026). As of Oct 2026.
Building Regulations 2010 regs 18 and 20 and Sch 3; Building Act 1984 s.36(4), as extended by Building Safety Act 2022 s.39
A registered engineer must do or directly supervise the gas work, and a scheme member self-certifies only their own work. Anything else goes to building control.
Asbestos
Presume asbestos in older buildings
In Great Britain, presume asbestos in buildings from before 2000 in boiler cupboard linings, flue pipes, textured coatings and old storage heaters until surveyed, and ask for the asbestos register on non-domestic jobs. Most work on lagging, sprayed coating and insulating board needs a licensed contractor. When unsure, stop. As of Oct 2026.
Control of Asbestos Regulations 2012, reg 4
A card proves registration today for the categories printed on it, not that a job was done properly: for that, ask for the job's certificate and notification number. Check the card and the Gas Safe Register or the scheme's member search on the day, before each type of job.
Asked in Greymill
Gas work must be done or directly supervised by a registered engineer, and a scheme member self-certifies only their own work.
Offer her a report: inspect both and write it up, promising no certificate.
The sign-off itself goes to building control, through a council regularisation application (an after-the-event sign-off).
Why it matters for her sale: a new boiler that was never notified surfaces when the house is sold.
In England, a Gas Safe business notifies a new boiler through Gas Safe within 30 days of completion (As of Oct 2026).
Unvented hot water storage over 15 litres needs a G3-qualified installer and is notified too (As of Oct 2026).
Often missed: in England, building control can now enforce for 10 years after completion (As of Oct 2026).
Happy to draft your report wording so it is clear no certificate is given.
Ask it about your own business
Paste this into Greymill with your own figures, and Rules & Licensing works it through for your business.
I run a plumbing, heating or electrical business in the UK. We work in [England, Wales, Scotland or Northern Ireland]. My engineers are [names, with their Gas Safe categories, electrical scheme, G3, F-gas and other cards]. We mostly do [types of job]. Check which jobs each engineer can legally take, which of our jobs need notifying and by when, and set up a renewal diary for every registration, assessment and card.
More for plumbing, heating and electrical in the UK
- My diary is full but nothing is left over: what should my charge-out rate and call-out fee be?Your engineers are paid for every hour but you only bill some of them, so build the rate from the hours you sell, not the hours you pay.Read the lesson
- Busy all summer on installs, yet the bank account is emptiest when the diary is fullestBreakdowns pay on the day, but installs, heat pump vouchers and letting agents pay late, so plan cash by the week, not by the season.Read the lesson
- Which VAT rate goes on the invoice: heat pump, boiler, wet room or new build?The VAT rate depends on what you install, for whom and in what kind of building, and charging too little comes out of your own margin.Read the lesson
- I went out for a repair and sold a new boiler: can the customer cancel?A homeowner's cancellation right, the emergency exception and the call-out fee all turn on what you put in writing before you started.Read the lesson
- My engineers run their own vans and carry CIS cards, so they are self-employed, aren't they?Status, travel time, on-call, holiday pay and who may work on gas all follow how the work is really done, not what the paperwork says.Read the lesson
- Letting agents want me to take on their landlords' deadlines: how do I win the work safely?Landlord and agent work is won on reliability, so sell the diary, price the failed visit and keep the legal duty where it belongs.Read the lesson
- The appliance is dangerous, or the customer blames my repair for a flood: what do I do first?When a job turns dangerous or a customer blames you for damage, the order of your first steps and what you write down matter most.Read the lesson
Open the interactive lesson · Every plumbing, heating and electrical lesson · What Greymill knows about the trade
Sources
The primary sources behind this lesson, checked Oct 2026.
- GSIUR reg 3(3) (Registrations, cards and competence by trade)
- Registration and ACS rules (Registrations, cards and competence by trade)
- Current schemes list, Electrical installations, updated 17 September 2026 (Registrations, cards and competence by trade)
- www.ecscard.org.uk (Registrations, cards and competence by trade)
- Water Fittings Regulations regs 5, 6 (Registrations, cards and competence by trade)
- Approved Document G, requirement G3 (Registrations, cards and competence by trade)
- HSWA 1974 s.33 and Sch 3A (Gas safety LAW, notification and the unsafe situations procedure)
- reg 26(9) (Gas safety LAW, notification and the unsafe situations procedure)
- reg 30 (Gas safety LAW, notification and the unsafe situations procedure)
- reg 34 (Gas safety LAW, notification and the unsafe situations procedure)
- Publication and withdrawal dates (Electrical work: BS 7671, part P, certificates, EICR coding, DNO and EV)
- reg 12(6A); reg 20 (Electrical work: BS 7671, part P, certificates, EICR coding, DNO and EV)
- Best Practice Guide 4 (Electrical work: BS 7671, part P, certificates, EICR coding, DNO and EV)
- EREC G98 and G99 (Electrical work: BS 7671, part P, certificates, EICR coding, DNO and EV)
- DESNZ asset-visibility call for evidence, Connect Direct and G98/G99; GOV.UK device-registration process (Electrical work: BS 7671, part P, certificates, EICR coding, DNO and EV)
- SI 2021/1467 regs 4 to 7, Sch 1 (Electrical work: BS 7671, part P, certificates, EICR coding, DNO and EV)
- reg 4 (Water fittings, unvented hot water, drainage and legionella)
- s.74 (Water fittings, unvented hot water, drainage and legionella)
- reg 5 and table (Water fittings, unvented hot water, drainage and legionella)
- Sch 2 para 15 and the backflow tables (Water fittings, unvented hot water, drainage and legionella)
- Byelaws 2014 (Water fittings, unvented hot water, drainage and legionella)
- Gas emergency numbers (Who must sign off: time-critical steps first)
- RIDDOR 2013 reg 11(2) (Who must sign off: time-critical steps first)
- Building Regulations 2010 reg 20 (Who must sign off: time-critical steps first)
- CCR 2013 regs 31, 36(6) (Who must sign off: time-critical steps first)
- GSIUR reg 36(6) (Who must sign off: time-critical steps first)
- SI 2020/312 reg 3(4) (Who must sign off: time-critical steps first)
- Work at Height Regulations 2005 reg 2 (definition of work at height) (Pitfalls that embarrass the product)
- What you can get (Pitfalls that embarrass the product)
- Using HCFCs in existing equipment (Pitfalls that embarrass the product)
- Notice 708/6 (Pitfalls that embarrass the product)
- When you must register (Pitfalls that embarrass the product)
- Building Regulations 2010 reg 18; council decision and requirements, not a promised certificate (Hard cases: gas, water and heating)
- CRA ss.49, 51 (Hard cases: gas, water and heating)
- Class G (Hard cases: gas, water and heating)
- Management Regulations 1999 reg 3(6) (Health and SAFETY on the job)
- regs 4, 9 (Health and SAFETY on the job)
- 2005 Regulations (Health and SAFETY on the job)
- SI 1997/1713 (Health and SAFETY on the job)
- CDM 2015 regs 6, 7 (Health and SAFETY on the job)
- Reporting timescales (Health and SAFETY on the job)