Requirements for Electrical Installations, IET Wiring Regulations, Eighteenth Edition, BS 7671:2018+A4:2026

What is BS 7671 – IET Wiring Regulations about?

The IET Wiring Regulations is the national standard for electrical installations in domestic, commercial and industrial settings. It is the essential standard for all those concerned with the design, installation, certification and maintenance of electrical installations. Amendment 4:2026 is a major update to BS 7671:2018, The IET Wiring Regulations, Eighteenth Edition.

BS 7671:2018+A4:2026 is a consolidated publication which incorporates all previous amendments to the standard. New inclusions within BS 7671:2018+A4:2026 are: Stationary Secondary Batteries where the purpose is for electrical storage and supply of electrical installations; Functional earthing and functional equipotential bonding for information and communication technology (ICT) equipment and systems; a new section on Power over Ethernet (PoE) and a major revision of Section 710 Medical Locations and the inclusion of a schedule of test results for recording the resistance of supplementary protective equipotential bonding conductors.

From 15th April 2026 you will need to have a copy of BS 7671:2018+A4:2026, known as 'the orange book'.

Who is BS 7671 – IET Wiring Regulations for?

BS 7671 on the requirements for electrical installations can be adopted by:

• Electrical contractors
• Electrical installation engineers
• Wiring and installation inspection engineers
• Electrical systems designers and installers
• Manufacturers of electrical cable, luminaires, sockets, junction boxes, ducting, fuse boards, tests and safety equipment, switches etc
• Regulators

What does BS 7671 – IET Wiring Regulations cover?

BS 7671 on the requirements for electrical installations sets out requirements that apply to the design, erection and verification of all new electrical installations and additions and alterations to existing electrical installations in the UK.

Although not a statutory document, BS 7671 sets the standard for how electrical installations should be done in the UK (and many other countries) and enables compliance with the law.

Why should you use BS 7671 – IET Wiring Regulations?

BS 7671 on the requirements for electrical installations is the most widely accepted way to evidence compliance with statutory requirements. In addition:

• It provides a single reference point for almost all domestic and similar electrical installations
• It increases the safety of electrical installations
• It supports the sustainable development of renewable sources of electricity
• It helps users stay up to date with new and innovative technologies
• It improves the efficiency of installations
• It’s the product of consensus among a comprehensive group of stakeholders

BS 7671 contributes to UN Sustainable Development Goal 7 on ensuring access to affordable, reliable, sustainable and modern energy for all; Goal 9 on industry, innovation and infrastructure; Goal 11 on making cities and human settlements safe, resilient and sustainable; and Goal 13 on taking urgent action to combat climate change and its impacts.

We offer customers a wide range of delivery options from Free (7-10 working days) ... right up to by Next Day by 9am (subject to location and stock availability).

• Simply choose your preferred service when checking out
• We show "live" stock levels for all publications
• Orders received after 3:45pm will be processed on the next working day.
• Unless specifically requested, our delivery partners will not attempt a weekend delivery

We offer all customers a "No Quibble" 28 day returns policy.

If you need to return a title for any reason ...

• Contact our customer services team first to explain what you are returning and the reason
• Request a Returns Authorisation Number
• We will email you this and a link to arrange your return quickly & easily via Royal Mail
• Take your return to your nearest Post Office and they will do the rest

Please refer to our Returns page for full details & charges.