Staying Ahead of 18th Edition Amendment 4

19-01-2026

The IET and BSI have confirmed that Amendment 4 (2026) to BS 7671:2018, the 18th Edition of the IET Wiring Regulations, will be published on 15 April 2026. The amendment can be implemented immediately upon publication, with the current standard BS 7671:2018 + A2:2022 + A3:2024 being withdrawn six months later. From that point, BS 7671:2018 + A4:2026 will become the definitive British Standard for all new low-voltage electrical installations, additions and alterations to existing systems, and periodic inspection and testing.

Amendment 4 introduces several significant technical changes reflecting the rapid development of electrical technologies. These include a new chapter on stationary secondary batteries used for electrical storage and supply, supporting the growing integration of renewable energy systems. There is also a new section on functional earthing and functional equipotential bonding for information and communication technology (ICT) equipment, alongside a dedicated section on Power over Ethernet (PoE) installations.

A major revision of Section 710 (Medical Locations) has been made, including the addition of a schedule of test results to record the resistance of supplementary protective equipotential bonding conductors, strengthening safety and compliance requirements in healthcare environments.

This amendment represents the second full consolidation of the 18th Edition, following earlier updates in 2020, 2022, and 2024. It also incorporates Amendment 3:2024 into the main document and continues the UK’s alignment with CENELEC Harmonized Documents and IEC standards, ensuring consistency with international best practice.

Industry bodies including NICEIC, NAPIT and SELECT encourage electrical professionals to familiarise themselves with the changes when published. Businesses will need access to the updated Wiring Regulations to maintain compliance with scheme requirements and remain aligned with evolving technologies and the UK’s clean energy ambitions.

More information is available at www.docs-store.co.uk/bs7671amendment4