IET and BSI publish Amendment 4 (2026) to BS 7671:2018 (IET Wiring Regulations)

Published: Thu 15 Jan 2026

IET and BSI publish Amendment 4 (2026) to BS 7671:2018 (IET Wiring Regulations) 

The Institution of Engineering and Technology (IET) together with BSI have today signed off the content for Amendment 4 (2026) to the standard Requirements for Electrical Installations (BS 7671:2018) (18th Edition of the IET Wiring Regulations). 

Significant changes include:  

• 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)
• a major revision of Section 710 Medical Locations and the inclusion of a schedule of test results for recording the resistance of supplementary protective equipotential bonding conductors. 
• Amendment 4 can be implemented immediately when published on 15 April 2026 and the previous version, BS 7671:2018+A2:2022+A3:2024, will be withdrawn six months later. 

This essential update to the IET Wiring Regulations will form the UK national standard for: 

• all new low voltage electrical installations
• additions and alterations to existing installations  
• periodic inspection and testing of existing installations.  

The IET and BSI encourage all electrical professionals to ensure they become familiar with the changes when published. 

Members of the committee responsible for the technical content of BS 7671, JPEL/64, are not permitted to release any further information before the publication date. 

Mark Coles, Head of Technical Regulations at the IET, said: “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UK and it is imperative that the industry is ready to work to this new amendment before BS 7671:2018+A2:2022+A3:2024 is withdrawn.”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 said: “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.”  

Further changes are included throughout all parts of BS 7671:2018+A4:2026, including the incorporation of Amendment 3:2024 to BS 7671:2018 as part of the main document. 

This Amendment sees the further adoption of CENELEC Harmonized Documents and IEC standards as the UK continues the inclusion of standards for new and developing technologies. 

BS 7671:2018+A4:2026 is available for pre-order via theiet.org/GetTheRegs - you can also learn more about the IET’s guidance and training packages here too. 

ENDS

Notes to Editors

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Sarah Jenkins
External Communications Manager
Email: SarahJenkins@theiet.org 

About BSI 

BSI is the business improvement and standards company that enables organizations to turn standards of best practice into habits of excellence, ‘inspiring trust for a more resilient world’. For over a century BSI has driven best practice in organizations around the world. Working with over 77,500 clients across 195 countries, it is a truly global business with skills and experience across all sectors including automotive, aerospace, built environment, food and retail and healthcare. Through its expertise in Standards and Knowledge, Assurance Services, Regulatory Services and Consulting Services, BSI helps clients to improve their performance, grow sustainably, manage risk and ultimately become more resilient.  

To learn more, please visit: www.bsigroup.com   

Please can any media requests also be forwarded to: 

Steph Croucher
BSI 
Tel: +44 (0)20 8996 6330 
Email: pressoffice@bsigroup.com