The electrotechnical trade body SELECT is calling on contractors across Scotland to familiarise themselves with the newly completed Amendment 4 (2026) to BS 7671:2018.

The update, also known as the 18th Edition of the IET Wiring Regulations, was recently finalised by the Institution of Engineering and Technology (IET) and the British Standards Institution (BSI).

Scheduled for release in April, BS 7671:2018+A4:2026 introduces several critical changes to industry standards. Notable additions include a new chapter dedicated to stationary secondary batteries used for electrical storage, along with a new section regarding Power over Ethernet (PoE).

Further updates include a section on functional earthing and equipotential bonding for ICT systems and a significant overhaul of Section 710, which governs medical locations. This revision also introduces a specific schedule for recording the resistance of supplementary protective equipotential bonding conductors.

Bob Cairney, Director of Technical Services at SELECT, said: "The association welcomes this latest amendment which is an essential update to continue to provide safe electrical installations across the UK.  

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"SELECT has participated with the IET and other industry bodies in the development of BS 7671 for many years through our contributions to the National Wiring Regulations JPEL/64 committee and we recognise the IET as the authority for electrical installations in the UK.  

"JPEL/64 carefully considers all necessary updates to the regulations to ensure they continue to meet the needs of the industry and Amendment 4 continues the thread of embracing new technologies. 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 set for publication on 15 April 2026 and can be implemented immediately. The existing version, BS 7671:2018+A2:2022+A3:2024, will be officially withdrawn six months later on 15 October. The new document will also incorporate Amendment 3:2024 and further align UK standards with CENELEC Harmonized Documents and IEC standards.

Robert McGoogan, SELECT's Director of Technical Services Designate, added: "BS 7671 underpins safe, modern electrical infrastructure and is essential for delivering the electrification needed to meet net zero ambitions.  

"Amendment 4 is an essential update to these regulations and will form the UK national standard for all-new low voltage electrical installations, additions and alterations to existing installations and periodic inspection and testing of existing installations.  

"As the electrification of society continues, it is therefore essential for contractors to keep abreast of the latest updates and we would encourage all members to familiarise themselves with Amendment 4 and its implications when it becomes available in April."

To assist the industry in transitioning to the new standards, SELECT will feature detailed discussions on Amendment 4 during its upcoming series of Toolbox Talks. Sponsored by Aico, these sessions will take place at 13 different locations throughout Scotland during May, June, and July.