BS 7671 Amendment 4: What Electricians Must Do Before October 2026

The IET and BSI published Amendment 4 to BS 7671:2018 on 15 April 2026. From that date, the updated standard — officially titled BS 7671:2018+A4:2026 and widely known as the Orange Book — can be used immediately for all new electrical work.

But here is the date that really matters: 15 October 2026.

That is when the previous version, BS 7671:2018+A2:2022+A3:2024 (the Brown Book), is formally withdrawn. From that point on, Amendment 4 becomes the only recognised UK national standard for the design, installation, inspection and testing of low-voltage electrical installations. If your work falls under BS 7671 — and for most UK electricians, it does — you need to be ready well before that date.

This guide explains exactly what has changed, who is affected, and the practical steps you need to take now.

What is BS 7671:2018+A4:2026?

BS 7671, commonly known as the IET Wiring Regulations, is the UK’s national standard for electrical installation safety. It is not statute law in itself, but it is the recognised benchmark for demonstrating compliance with the Electricity at Work Regulations 1989, and competent person schemes — including NICEIC and NAPIT — require you to work to its current edition.

Amendment 4 is the fourth update to the 18th Edition, which was first published in 2018. Rather than issuing an entirely new 19th Edition, the IET and BSI have released a fully consolidated reprint that incorporates Amendments 2 and 3 alongside the new technical content. The result is a single, complete publication — the Orange Book — that replaces all previous 18th Edition versions from October 2026.

Amendment 4 is not a minor housekeeping update. It is the most significant revision to BS 7671 since Amendment 2 in 2022, and it introduces new chapters and sections that reflect the way electrical installations are genuinely changing: more battery storage, more connected systems, smarter buildings, and more complex healthcare environments.

What has changed in Amendment 4?

The headline additions are:

New chapter on stationary secondary batteries This is the most impactful change for domestic and commercial electricians. As solar-plus-storage systems, home battery units, and commercial energy storage installations become increasingly common, BS 7671 previously had no dedicated chapter covering them. Electricians were working to manufacturer guidelines and best practice recommendations without formal regulation. Amendment 4 changes that with a new chapter that sets out specific requirements for selection, erection, protection against electric shock and thermal effects, isolation and switching, ventilation, fire protection, and verification. If you install solar PV with battery storage, standalone home batteries, EV chargers with backup storage, or any commercial battery system, this chapter directly affects your work.

New section on Power over Ethernet (PoE) Modern commercial buildings increasingly rely on PoE technology to power devices such as LED lighting, security cameras, access control systems, and sensors directly through Ethernet cabling. Amendment 4 brings PoE explicitly within the scope of BS 7671 for the first time, introducing requirements around cable derating, protection, earthing, and load calculations. If you work on commercial fit-outs or smart building systems, you can no longer treat PoE as purely an IT concern.

New section on functional earthing for ICT systems Amendment 4 introduces a dedicated section on functional earthing and equipotential bonding for information and communication technology equipment and systems. This clarifies the distinction between protective earthing — which prevents electric shock — and functional earthing, which manages electromagnetic interference and maintains equipment performance. This is particularly relevant for data centres, server rooms, and ICT-heavy commercial installations.

Major revision of Section 710: Medical Locations The medical locations section has been substantially updated, with stronger requirements for resilience, classification, and testing, including a new schedule for recording the resistance of supplementary protective equipotential bonding conductors. Electricians working in hospitals, clinics, care homes, or any environment with medical-grade electrical requirements need to familiarise themselves with these revisions.

Who is affected?

Amendment 4 applies to anyone who designs, installs, inspects, or certifies electrical work in the UK. More specifically:

• Electricians and contractors carrying out new installations, additions, or alterations after 15 October 2026 must work to the Orange Book. That includes domestic, commercial, and industrial work.
• Inspection and testing engineers conducting periodic inspections (EICRs) must reference the updated standard once it becomes mandatory. Certification software, checklists, and documentation will need to be updated accordingly.
• Solar PV and battery storage installers are among the most directly affected by the new battery chapter — arguably the biggest change in the entire amendment.
• Commercial electricians working on PoE-heavy environments, smart buildings, data centres, and healthcare sites will encounter multiple areas of new or revised regulation.
• Employers and business owners who employ electricians or are responsible for electrical installations at their premises should ensure their staff hold up-to-date qualifications and that their internal processes align with the new standard.

If you are certified with NICEIC, NAPIT, or another competent person scheme, you should check directly with your scheme provider about audit expectations after October 2026. NICEIC, for example, requires certified businesses to demonstrate access to the current edition of BS 7671 as part of its scheme rules.

What do you need to do — and when?

Step 1: Understand what has changed

You cannot comply with a standard you have not read. The full Orange Book is available for purchase online. If you currently hold a valid 18th Edition qualification, you do not need to resit the full exam — but you do need to update your knowledge to cover the new and revised sections in Amendment 4.

Step 2: Complete online training

A dedicated Amendment 4 update course is the most efficient route for electricians who already hold an 18th Edition qualification. These focused courses cover the key technical changes without requiring you to repeat content you already know. The course is delivered by Virtual College fully online.

Step 3: Update your documentation

Review your standard method statements, test sheets, EICR templates, and certification documents. The new chapters — particularly for battery installations and medical locations — introduce additional data requirements and recording obligations. Getting your paperwork in order before October 2026 avoids problems at the point of inspection or certification.

Step 4: Review upcoming projects

Identify any projects in your pipeline involving battery storage, PoE systems, ICT infrastructure, or healthcare environments. For any work scheduled beyond the transition period, you should plan and specify to BS 7671:2018+A4:2026 from the outset, rather than mid-project.

Step 5: Confirm your scheme obligations

If you are a member of a competent person scheme, confirm when they expect evidence of Amendment 4 compliance. Most schemes will require you to demonstrate access to the Orange Book and up-to-date qualification evidence from October 2026.

What happens if you are not ready by October?

After 15 October 2026, the previous edition of BS 7671 is no longer the recognised standard. Continuing to work to the withdrawn edition creates professional and legal risk: work may not be certifiable to current standards, competent person scheme certification could be at risk, and — most importantly — installations may fall short of the safety expectations that Amendment 4 has been designed to address.

This is not a theoretical concern. Amendment 4 was introduced because electrical installations are genuinely changing in ways the previous regulations did not fully account for. Battery energy storage, PoE infrastructure, and modern healthcare environments all present risks that require specific technical guidance. Working without that guidance is not just a compliance issue — it is a safety one.

The bottom line

The six-month transition period between April and October 2026 is a reasonable window, but it is not an invitation to delay. Training courses fill up. Documentation takes time to update. Projects in the pipeline need to be planned to the new standard.

The electricians and businesses who act now — reading the Orange Book, booking update training, and reviewing their processes — will be compliant, confident, and competitive by October. Those who leave it until the summer risk a scramble that no one wants.

Virtual College’s 18th Edition Amendment 4 training courses are designed to get you up to speed efficiently, with flexible online learning that fits around your working schedule. Whether you need a full qualification or a focused update course, you can start today.

View 18th Edition Amendment 4 training.