IET Wiring Regulations 18th Edition BS 7671:2018+A4:2026 – Amendment 4
The essential electrical installation standard, fully consolidated and updated for Amendment 4:2026.
BS 7671:2018+A4:2026 Requirements for Electrical Installations, IET Wiring Regulations, Eighteenth Edition is the national standard for electrical installations in domestic, commercial and industrial settings.
Essential for professionals involved in the design, installation, certification and maintenance of electrical installations, this major Amendment 4 publication brings the requirements of BS 7671 together in one fully consolidated edition.
BS 7671:2018+A4:2026 incorporates all previous amendments to the 18th Edition and introduces important new and revised requirements covering areas including stationary secondary batteries, ICT earthing and bonding, Power over Ethernet (PoE), Medical Locations and supplementary protective equipotential bonding test results.
Known as the “orange book”, this is the key reference for electrical professionals working with the latest requirements of the IET Wiring Regulations.
Why You Need BS 7671:2018+A4:2026
- The national standard for electrical installations in domestic, commercial and industrial settings
- Essential for those involved in design, installation, certification and maintenance
- Fully updated for Amendment 4:2026
- A consolidated publication incorporating all previous amendments to BS 7671:2018
- Includes major new and revised requirements across important areas of modern electrical installation work
- Includes a new section covering Power over Ethernet (PoE)
- Features a major revision of Section 710 – Medical Locations
- Includes requirements relating to stationary secondary batteries
- Includes new guidance relating to functional earthing and functional equipotential bonding for ICT equipment and systems
What‘s New in Amendment 4:2026?
Amendment 4:2026 represents a major update to BS 7671:2018, The IET Wiring Regulations, Eighteenth Edition.
The consolidated BS 7671:2018+A4:2026 publication introduces a number of significant additions and revisions, including:
- Stationary Secondary Batteries where the purpose is electrical storage and supply of electrical installations
- Functional earthing for information and communication technology (ICT) equipment and systems
- Functional equipotential bonding for ICT equipment and systems
- A new section covering Power over Ethernet (PoE)
- A major revision of Section 710 – Medical Locations
- A new schedule of test results for recording the resistance of supplementary protective equipotential bonding conductors
One Consolidated Edition
BS 7671:2018+A4:2026 is a consolidated publication, meaning that all previous amendments to the 18th Edition have been incorporated into this edition.
This gives electrical professionals one current reference containing the requirements of BS 7671 together with the changes introduced through Amendment 4:2026.
Who Needs the IET Wiring Regulations?
The IET Wiring Regulations are essential for professionals concerned with electrical installations across domestic, commercial and industrial settings.
- Professionals responsible for electrical installation design
- Those carrying out electrical installation work
- Professionals involved in certification
- Those responsible for maintenance of electrical installations
From 15th April 2026, you will need to have a copy of BS 7671:2018+A4:2026, known as the “orange book”.
The Essential Reference for Electrical Installation Work
BS 7671 sits at the heart of electrical installation work, providing the national standard used across domestic, commercial and industrial environments.
With Amendment 4 introducing new requirements covering areas such as energy storage, ICT systems and Power over Ethernet, alongside a major revision of Medical Locations, the 2026 consolidated edition brings important developments together in one essential publication.
For anyone responsible for designing, installing, certifying or maintaining electrical installations, the 18th Edition Amendment 4 Wiring Regulations is a core professional reference.
Product Details
| Features | |
| Standard | BS 7671:2018+A4:2026 |
| Edition | 18th Edition – Amendment 4 |
| Subject | Electrical Regulations |
| Publication Year | 2026 |
| Pages | 640 |
| ISBN-13 | 978-1-83953-972-5 |
| Part Number | PIETREG184 |
| Format | Paperback Book |
| Known As | The Orange Book |