18th Edition - Amendment 4

The 18th Edition Amendment 4 (BS 7671:2018 +A4:2026) is the latest update to the IET Wiring Regulations, setting out revised requirements for the design, installation, inspection, and testing of electrical installations across the UK.

Published by the IET and BSI, Amendment 4 reflects the growing use of modern technologies such as battery energy storage systems, Power over Ethernet (PoE), and smart building infrastructure.

Amendment 4 introduces new and updated sections covering stationary secondary batteries, functional earthing for ICT systems, PoE installations, and revised requirements for medical locations, ensuring electrical installations remain safe, consistent, and fit for future technologies.

Published on 15 April 2026, Amendment 4 can be implemented immediately. From 15 October 2026, the previous version (BS 7671:2018+A2:2022+A3:2024) is withdrawn, making Amendment 4 the sole recognised standard for all electrical work, alterations, and inspection and testing in domestic, commercial, and industrial environments.

YESSS Electrical supplies a wide range of products aligned with 18th Edition Amendment 4 requirements including guides to help electricians, contractors, and specifiers stay compliant with the latest wiring regulations.

Whether you're preparing for the October 2026 deadline or upgrading installations to meet current standards, find trusted, regulation‑ready solutions at YESSS Electrical.