On 15 January 2026, the Institution of Engineering and Technology (IET) and the British Standards Institution confirmed the publication of Amendment 4, 2026 to BS 7671:2018 IET Wiring Regulations, the UK standard for electrical installations. In large, Amendment 4 reflects how electrical systems within our buildings are evolving.
BS 7671 sets out the requirements for the design, installation, inspection, testing, and verification of electrical installations in the UK. It covers system design, protection and safety measures, equipment and wiring standards, specialist locations such as healthcare environments, inspection and testing procedures, and guidance for alterations and additions to existing installations. While BS 7671 is not law, it is widely recognised as the standard for compliance with the Electricity at Work Regulations and Building Regulations.
Amendment 4 will be published on 15 April 2026, and may be implemented immediately from that date. The current consolidated edition will be withdrawn six months later. This update reflects changes in technology, modern methods of construction, and evolving expectations around electrical safety across residential, commercial, healthcare, and specialist environments.
Why This Matters
BS 7671 underpins how electrical installations are designed, installed, inspected, and tested throughout the UK. It applies to new low voltage installations, as well as additions, alterations, and periodic inspection regimes on existing systems.
Electrical designers, installers, surveyors, and compliance teams should understand the changes introduced by Amendment 4 ahead of implementation, to ensure ongoing safety, compliance, and confidence for clients and building users.
Key Changes Introduced by Amendment 4
Amendment 4 introduces several important updates that recognise emerging technologies and sector specific risks.
A new dedicated chapter now addresses stationary secondary batteries, used for electrical storage and supply within installations. This reflects the rapid growth of energy storage systems linked to renewables, electric vehicle charging, and smart building technologies.
Functional earthing and equipotential bonding requirements have been introduced for information and communication technology systems. This provides clearer guidance for safety and reliability in data rich and digitally connected environments.
Power over Ethernet now has its own dedicated section. This recognises the increasing use of PoE to supply power to lighting, sensors, access control systems, and other low voltage devices, particularly within commercial and institutional buildings.
Section 710, which covers electrical installations in medical locations, has been significantly revised. Updates include a schedule for recording the resistance of supplementary protective equipotential bonding conductors, which is critical for safety management and compliance within healthcare settings.
Timing and Transition
From 15 April 2026, electrical works may be designed and installed in accordance with Amendment 4. Six months after publication, the previous consolidated edition will be withdrawn. This transition period is intended to allow organisations time to update procedures, training, and technical documentation.
Industry bodies and certification schemes are already preparing guidance, training, and technical support to help professionals adapt to the new requirements.
What This Means
At Ventro, our focus is on delivering safe, compliant, and well managed electrical services. Amendment 4 has implications for design, installation, inspection, testing, and reporting, particularly in complex environments such as healthcare and large commercial estates.
Our teams are reviewing the detailed requirements, and updating training processes and operational standards, to ensure all works continue to align with the latest national guidance.
Next Steps
Electrical professionals should really familiarise themselves with the updated standard as soon as it is published, review current and upcoming projects for any impact, and ensure relevant training and competence updates are in place.
Amendment 4 is being introduced to keep pace with how electrical systems are continuing to evolve. Early understanding and preparation will support safer installations, stronger compliance, and better long term outcomes for buildings and the people who use them.
