IET Wiring Regulations 18th Edition and Guidance Note 3 Bundle (A4:2026)

IET Wiring Regulations 18th Edition and Guidance Note 3 Bundle (A4:2026)

IET Wiring Regulations 18th Edition and Guidance Note 3 Bundle (A4:2026) brings together the core UK standard for electrical installations and the go-to reference for inspection and testing. It’s ideal for electricians, designers, specifiers and inspectors working across domestic, commercial and industrial installations, where compliance, verification and documentation all have to stand up to scrutiny.

The bundle includes BS 7671:2018+A4:2026 (the consolidated 18th Edition Wiring Regulations, often called the orange book) plus IET Guidance Note 3: Inspection & Testing updated to match the same edition. BS 7671:2018+A4:2026 incorporates all previous amendments and adds major updates for modern installations, including stationary secondary batteries, functional earthing and functional equipotential bonding for ICT systems, a new Power over Ethernet (PoE) section, and a significant revision to Section 710 Medical Locations, plus improved test recording for supplementary bonding resistance.

Amendment 4 is published on 15 April 2026 and can be implemented immediately, with the previous version withdrawn six months later, so having the current edition matters for new work and ongoing inspection/testing activity.

Guidance Note 3 then turns the regulations into practical inspection-and-testing workflows, supporting competent electricians and those studying inspection and testing qualifications. It includes updated guidance on conductor identification, stationary secondary batteries, prosumers’ electrical installations, recommended initial inspection frequencies, and maximum permissible measured earth fault loop impedance (EFLI).

Key Features

• Bundle includes BS 7671:2018+A4:2026 and IET Guidance Note 3: Inspection and Testing updated to A4:2026
• BS 7671 is the UK national standard for electrical installations in domestic, commercial and industrial settings
• BS 7671:2018+A4:2026 is a consolidated publication incorporating all previous amendments
• New and revised coverage includes stationary secondary batteries for electrical storage and supply within installations
• Includes functional earthing and functional equipotential bonding guidance for ICT equipment and systems
• Includes a dedicated section on Power over Ethernet PoE
• Major revision of Section 710 medical locations plus improved test recording for supplementary bonding resistance
• Amendment 4 published 15 April 2026 and can be implemented immediately, with the previous version withdrawn six months later
• Guidance Note 3 supports accurate inspection, testing, verification and documentation
• Guidance Note 3 updates include conductor identification, prosumers installations, recommended inspection frequencies and maximum permissible measured EFLI