The IET Wiring Regulations are set for another update, with a new chapter on stationary batteries, guidance on Power over Ethernet, and a major revision to medical locations.
Amendment 4 (2026) to BS 7671:2018 is scheduled to be published on April 15, 2026, and can be implemented immediately from that date. The current version, BS 7671:2018+A2:2022+A3:2024, will then be withdrawn six months later.
For contractors and duty holders, the key point is timing: the industry will have a defined transition window, but once the existing edition is withdrawn, work will be expected to align with the updated requirements.
What’s changing in Amendment 4?
The IET and BSI say Amendment 4 includes several significant additions and revisions, reflecting the continued integration of newer technologies into mainstream electrical design, installation, and verification.
Among the headline updates are:
- A new chapter on Stationary Secondary Batteries, where the purpose is for electrical storage and supply of electrical installations.
- A new section on functional earthing and functional equipotential bonding for information and communication technology (ICT) equipment and systems.
- A new section on Power over Ethernet (PoE), reflecting the growth of PoE-driven building services and connected devices.
- A major revision to Section 710 (Medical Locations), alongside the inclusion of a schedule of test results for recording the resistance of supplementary protective equipotential bonding conductors.
Further changes are also included throughout all parts of the updated document, including the incorporation of Amendment 3:2024 into the main body of BS 7671, rather than leaving it as a separate add-on.
The amendment also continues the UK’s alignment with European and international standards, with further adoption of CENELEC Harmonised Documents and IEC standards, as BS 7671 evolves alongside developing technologies.
Mark Coles, Head of Technical Regulations at the IET, noted, “The IET is the authority for electrical Installations in the UK and ensures that the National Wiring Regulations Committee carefully considers all necessary updates to the Regulations to ensure they best meet the needs of the industry.
“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 safe electrical installations in the UK and it is imperative that the industry is ready to work to this new amendment before BS 7671:2018+A2:2022+A3:2024 is withdrawn.”
Sebastiaan van Dort, Director of Energy and Sustainability at BSI, added, “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.”
BS 7671:2018+A4:2026 will be available for pre-order via the IET, with publication confirmed for April 15, 2026.
