The On-Site Guide is an essential guide to BS 7671. It incorporates the extensive changes in BS 7671:2018, making this a vital guide for keeping up to date. It enables the competent electrician to deal with installations (up to 100 A, 3-phase) providing essential information in a convenient, easy-to-use format. This publication has been further updated to include two subsequent amendments to the IET Wiring Regulations as BS 7671:2018+A2:2022.BS 7671:2018+A2:2022 incorporates changes from the first amendment, published in 2020, regarding Electric Vehicle Charging Installations to provide greater guidance on embracing changing technology within this sector. Additional changes within the second amendment include protection against thermal effects and fire caused by electrical equipment, protection against voltage disturbances and electromagnetic disturbances, and a new chapter on prosumer's low-voltage electrical installations covering energy efficiency measures, the interface with the smart grid, the management of electricity consumption, the management of renewable sources of electricity, and energy storage.