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

The On-Site Guide is a practical companion to BS 7671, designed to help competent electricians carry out installations up to 100 A, 3-phase with confidence and accuracy. It presents essential information from the Wiring Regulations in a clear, easy-to-use format that supports safe, compliant decision-making on site.

This edition has been updated to reflect the full requirements of BS 7671:2018+A4:2026, incorporating the latest amendments. It remains a vital reference for keeping up to date with current installation practice and applying the Regulations correctly in day-to-day work.