For decades, BS 7671, known as the IET Wiring Regulations, has been the definitive reference for electrical professionals across the United Kingdom.

Now, with the arrival of the amendment 4:2026 imminent, the standard is not just keeping pace with change, but setting the agenda for the future of safe, modern and sustainable electrical infrastructure.

As the UK accelerates towards ambitious clean energy goals and the electrification of everything from homes to hospitals, the new BS 7671:2018+A4:2026 is more relevant than ever. Let’s explore what’s new, why it matters and why pre-ordering the latest edition is a smart move for anyone involved in electrical design, installation, or inspection.

You can now pre-order the hardcopy of BS 7671:2018+A4:2026 (IET Wiring Regulations) and be among the first to receive it on the official publication date.

Pre-order your copy here.

What is BS 7671:2018+A4:2026?

BS 7671, or the IET Wiring Regulations, is the UK’s national standard for the design, erection and verification of electrical installations. It brings together European Harmonized Documents (HDs) and international standards, providing a single, authoritative source for all new and amended electrical installations in the UK.

The regulations apply to a vast range of environments, from domestic and commercial buildings to specialized locations like swimming pools, highway equipment and photovoltaic power systems.

The standard is not static. It evolves to reflect new technologies, emerging risks, and the collective expertise of the industry. Amendment 4:2026 is the latest milestone in this journey, introducing essential updates that address the realities of today’s electrical landscape.

Why does Amendment 4 to the wiring regulations matter?

The pace of technological change in the electrical sector is relentless.

Energy storage, smart systems, Power over Ethernet (PoE) and advanced medical installations have moved from niche applications to everyday reality. With almost 50% of electricians planning to expand into solar, EV charging and heat pump installations, future-ready standards are no longer optional, but essential.

BS 7671:2018+A4:2026 keeps the UK’s Wiring Regulations fit for purpose, delivering clear, practical guidance for both established practices and emerging technologies.

As Sebastiaan van Dort, Director of Energy & Sustainability at BSI, puts it:

“BSI is proud to jointly publish this vital standard with the IET at a time when the UK is accelerating towards its 2030 clean energy goals. BS 7671 underpins safe, modern electrical infrastructure, essential for delivering the electrification needed to meet net zero ambitions.”

Consider this: there are currently only around 4,000 heat pump installers in the UK - a number that must grow dramatically to meet government targets by 2028. Staying ahead with the latest requirements isn’t just about compliance; it’s about seizing opportunities, driving innovation and safeguarding lives and property in a rapidly changing world.

Who needs BS 7671:2018+A4:2026?

The standard is directly relevant to:

• Electrical contractors.

• Electrical installation engineers.

• Wiring and installation inspection engineers.

• Electrical systems designers and installers.

It is also highly relevant to manufacturers and suppliers of electrical equipment - cables, luminaires, sockets, junction boxes, fuse boards, and safety equipment - as well as anyone responsible for the safety and compliance of electrical systems in buildings and infrastructure.

For these professionals, BS 7671 is a daily tool, a mark of competence and often a legal requirement. Electricians must comply with the wiring regulations and are frequently required to be Part P registered, ensuring they have the knowledge and training to perform electrical work safely.

What’s new in BS 7671:2018+A4:2026?

Amendment 4 is not a minor update. It introduces several significant changes that reflect the latest industry needs and technological advancements. The key updates include:

• A new chapter on stationary secondary batteries: This addresses the requirements for electrical storage systems used to supply installations, supporting the integration of renewable energy and grid resilience.

• A new section on functional earthing and equipotential bonding for ICT equipment and systems: As information and communication technology becomes ever more integral to buildings, clear rules for earthing and bonding are essential for safety and performance.

• A new section on Power over Ethernet (PoE): With the rise of smart buildings and IoT, PoE is increasingly used to power devices via data cables. The new requirements ensure these systems are installed safely and reliably.

• A major revision of Section 710 (Medical Locations): This includes enhanced requirements and the introduction of a schedule of test results for recording the resistance of supplementary protective equipotential bonding conductors—critical for patient safety in healthcare environments.

• Incorporation of Amendment 3:2024: The latest amendment integrates previous updates, ensuring consistency and clarity across the standard.

• Further adoption of CENELEC Harmonized Documents and IEC standards: This aligns the UK’s regulations with European and international best practice, supporting trade and innovation.

Mark Coles, Head of Technical Regulations at the IET, highlights the significance of these changes:

“The Amendment continues the thread of embracing new technologies and the inclusion of a new section on Stationary Secondary Batteries is an exciting step into the future of renewable sources of energy and their integration into our lives. Amendment 4 is an essential update to provide for the safety of electrical installations in the UK and it is now imperative that the industry is ready to work to this amendment before BS 7671:2018+A2:2022+A3:2024 is withdrawn.”

With the publication of Amendment 4, the previous version—BS 7671:2018+A2:2022+A3:2024—will be officially withdrawn on 15 October 2026 but remains valid for six months after Amendment 4’s release. This transition period gives professionals time to review the changes, update their processes and ensure compliance. After this window, only the new standard will be recognized as the UK national standard for electrical installations.

Why you should get BS 7671:2018+A4:2026

BS 7671 is the most widely accepted way to demonstrate compliance with UK electrical safety legislation. Working to the latest standard is not just best practice, but often a contractual or regulatory requirement. Using the new amendment signals professionalism and a commitment to safety.

Other benefits include:

• Improved clarity and confidence

The standard provides clear, structured requirements for the design, installation and verification of electrical systems. This reduces ambiguity, minimizes risk, and helps professionals deliver safe, compliant work - whether in homes, offices, or complex environments like hospitals and data centres.

• Future-proofing and innovation

By addressing new technologies, Amendment 4 ensures that professionals can integrate modern solutions without compromising safety. This supports the transition to smart, sustainable infrastructure and helps organizations stay ahead of the curve.

• Risk management and safety

Electrical hazards can have devastating consequences, making robust safety practices non-negotiable. With 30% of electricians still not using lock-off kits, Amendment 4 reinforces these critical measures while enabling the safe integration of new technologies. The updated requirements are designed to prevent electric shock, fire and other risks, protecting both installers and end users. Enhanced provisions for medical locations and other critical systems further underline the standard’s role in safeguarding lives where reliability matters most.

• Sustainability and net zero goals

BS 7671 underpins the electrification needed to meet the UK’s net zero ambitions. By supporting the safe integration of renewable energy and efficient systems, the standard contributes to a more resilient and sustainable built environment.

How pre-order can benefit you

Pre-ordering BS 7671:2018+A4:2026 offers you a strategic advantage. Here’s why:

• Immediate access: By pre-ordering, you receive the hardcopy sent to you as soon as it becomes available. This means you can start working to the new requirements without delay, staying ahead of the compliance curve.

• Time to prepare: Immediate access gives you the opportunity to review the changes, update your documentation, brief your teams and align your projects before the old standard is withdrawn.

• Demonstrate leadership: Clients and partners expect up-to-date knowledge and compliance. Pre-ordering and working to the latest standard shows you are proactive, informed and committed to best practice.

• Stay competitive: As the industry transitions, those who move early will be best placed to win contracts, avoid compliance issues and deliver value to clients.

Ready to secure your copy? Pre-order BS 7671:2018+A4:2026 today and ensure you’re prepared for the future of electrical safety and compliance.