BS 7671 Amendment 4: What’s Changing from 15 April 2026 and Why It Matters

What is BS 7671 Amendment 4

BS 7671 is the UK standard used across commercial, industrial and domestic installations for design, installation and verification. Amendment 4 is the next update to the 18th Edition and has been signed off by the IET and BSI, with publication confirmed for 15 April 2026.

The key thing to know is this: Amendment 4 continues the trend of supporting modern technologies and tightening how requirements are applied, particularly around newer systems and clearer expectations.

Key changes confirmed so far

The IET and BSI have confirmed several significant additions and revisions, including:

A new chapter on stationary secondary batteries

A new chapter is being introduced covering stationary secondary batteries used for electrical storage and supply within installations. This matters for commercial sites adopting energy storage as part of resilience, peak shaving and renewables planning.

A new section on functional earthing and equipotential bonding for ICT systems

This is aimed at information and communication technology equipment and systems, which is highly relevant for offices, managed buildings, comms rooms, server areas and modern network infrastructure.

A new section on Power over Ethernet

Power over Ethernet is now common for access control, IP cameras, VoIP phones, smart building sensors and modern lighting control. The new section means clearer expectations for designers and installers working with PoE at scale.

A major revision to Section 710 medical locations

There is a major revision of Section 710 and the inclusion of a schedule of test results for recording resistance of supplementary protective equipotential bonding conductors. Not every commercial client will touch medical locations but the wider message is clear: improved consistency in testing and reporting.

Important note: the committee responsible for BS 7671 content is not permitted to release further detail before publication, so any deep technical breakdown should wait until April 2026 when the standard is live.

When Amendment 4 applies

• Publication date: 15 April 2026

• Can be implemented immediately from publication

• Previous version is withdrawn six months later (15 October 2026 is referenced by NICEIC as the end of the transition period for scheme expectations)

For practical planning, any new installations, additions, alterations and periodic inspection and testing carried out from mid April 2026 should reference BS 7671:2018 + Amendment 4:2026 where you are implementing it.

Why this matters for commercial clients

If you are responsible for commercial premises, compliance risk usually shows up in three places:

1) Audit readiness and documentation quality

Facilities teams and managing agents rely on reports that are consistent, clear and defensible. Amendment 4 is positioned as an essential update supporting safer installations and improved alignment with modern technologies.

2) Modern building systems are more connected than ever

PoE networks, ICT equipment and building control systems are now a core part of how sites operate. New dedicated sections should make it easier to specify, install and verify these systems without grey areas.

3) Energy storage is moving into the mainstream

More businesses are adding batteries to support renewables or resilience. A new chapter on stationary secondary batteries signals clearer requirements for design and integration.

If you want a safer way to manage this across sites, our commercial support is built around Statutory Compliance and Remedial Works.