IET On-Site Guide (BS 7671:2018+A4:2026) - 9th Edition

The essential pocket guide for quick, on-the-job electrical compliance.

The IET On-Site Guide is a vital tool for every electrician, providing a practical, simplified version of the Wiring Regulations for installations up to 100A (3-phase). This new 9th Edition has been fully updated to reflect Amendment 4:2026 (The Orange Book), ensuring you have the most current information at your fingertips without needing to perform complex calculations on-site.

This edition is now the definitive guide, consolidating all previous updates—including the recent Amendment 3:2024—into one easy-to-use manual.

Key Updates in the 9th Edition (Amendment 4):

• Stationary Secondary Batteries: Practical guidance on the safe installation of battery storage systems, reflecting the new Chapter 57.

• Power over Ethernet (PoE): Simplified requirements for installing data cabling used for power distribution (Section 716).

• ICT Systems: Updated rules for functional earthing and bonding for information technology equipment.

• Medical Locations: Revised guidance for electrical installations in clinical and healthcare environments (Section 710).

• Consolidated Tables & Values: Includes all updated earth fault loop impedance (Zs) values and cable sizing tables from the latest version of BS 7671.

Why Every Electrician Needs the On-Site Guide:

While the full "Orange Book" contains the complete regulations, the On-Site Guide is designed for the person on the tools. It takes the most commonly used parts of the regulations and presents them in a clear, accessible format with helpful diagrams and tables.

Ideal for:

• Electricians and Domestic Installers

• Maintenance Engineers

• Apprentices and Electrical Students

• Plumbers and Heating Engineers (wiring boilers/showers)

Important Compliance Dates:

• Published: 15th April 2026 (Implementable immediately).

• Mandatory: From 15th October 2026, all work must comply with Amendment 4.

Make sure your toolkit is up to date. Order the 9th Edition On-Site Guide today to stay compliant with the latest UK standards.