BS 7671:2018+A4:2026 18th Edition Wiring Regulations - Amendment 4

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The latest IET Wiring Regulations are now in force.

BS 7671:2018+A4:2026 (Amendment 4) is the current edition of the 18th Edition IET Wiring Regulations. Published on 15 April 2026, Amendment 4 became the required standard for new electrical installation work on 15 October 2026, following the withdrawal of the previous version.

If you design, install, inspect or test electrical installations in the UK, make sure you're working with the latest requirements.

Comply now and shop Amendment 4 Wiring Regulations, On-Site Guides, Guidance Notes and value packs all available at competitive prices with FREE standard UK mainland delivery.

Order online today or call 01380 820 003. We can’t be beaten on service. We won’t be beaten on price.

Why Amendment 4 Matters

The IET Wiring Regulations (BS 7671) set the benchmark for electrical installation safety across the UK. Amendment 4 introduces important technical updates and revisions to ensure installations remain safe, compliant and aligned with evolving industry practice.

From domestic installations to commercial and industrial projects, compliance with the latest edition is essential for:

• Electrical contractors
• Designers and consultants
• Inspectors and testers
• Training providers and colleges
• Certification bodies and scheme members
• The new standard became effective immediately on 15th April 2026.

Make sure you are working to the correct version.

What Has Changed in Amendment 4?

Amendment 4 introduces important updates to the 18th Edition IET Wiring Regulations, reflecting developments in electrical installation technology, safety and industry practice.

Key changes include:

• Stationary secondary batteries: A new chapter covering battery systems used for electrical energy storage and supply.

• Functional earthing and bonding: New requirements for information and communication technology (ICT) equipment and systems.

• Power over Ethernet (PoE): New requirements addressing electrical installations incorporating PoE technology.

• Medical locations: Significant revisions to Section 710, including updated requirements for supplementary protective equipotential bonding and associated testing.

Amendment 4 also incorporates Amendment 3:2024 and introduces further revisions throughout BS 7671.

For detailed technical guidance, visit the official IET Amendment 4 information page, or explore the supporting videos below.

Watch: Amendment 4 Explained

Frequently Asked Questions

When did Amendment 4 come into effect?

BS 7671:2018+A4:2026 was published on 15 April 2026 and became the current standard for new electrical installation work on 15 October 2026, following the withdrawal of the previous version.

Do I need a new copy of the Wiring Regulations?

Electrical professionals working to the latest requirements should use BS 7671:2018+A4:2026 (Amendment 4). The previous version, incorporating Amendments 2 and 3, was withdrawn on 15 October 2026.

Is Amendment 4 mandatory?

BS 7671 is not itself legislation, but it is the recognised UK national standard for electrical installations and is widely used to demonstrate compliance with relevant safety legislation. Amendment 4 is now the current edition.

Do existing electrical installations need upgrading to Amendment 4?

Not necessarily. Existing installations that complied with an earlier edition do not automatically require upgrading simply because Amendment 4 has been introduced. Their safety and suitability should be assessed according to the circumstances.

Do you offer discounts for bulk orders?

Yes. We offer competitive pricing for bulk purchases, businesses and training providers. Call 01380 820 003 to discuss your requirements or request a tailored quote.