What's changed in Amendment 4:2026?
We co-publish BS 7671 with the British Standards Institution (BSI) and lead the UK’s national Wiring Regulations committee, JPEL/64, ensuring the standard reflects both international developments and UK-specific needs.
Key areas of change include:
- A new chapter on Stationary Secondary Batteries, where the purpose is for electrical storage and supply of electrical installations.
- A new section on Functional earthing and functional equipotential bonding for information and communication technology (ICT) equipment and systems.
- A new section on Power over Ethernet (PoE).
- A major revision of Section 710 Medical Locations and the inclusion of a schedule of test results for recording the resistance of supplementary protective equipotential bonding conductors.
Transition period: Brown Book remains valid until October 2026
Although BS 7671:2018+A4:2026 has now been published, Amendment 3:2024 to BS 7671:2018 (the Brown Book) remains a valid standard until 15 October 2026.
During this period, electrical installers may work to either edition.
If you are currently using the Brown Book, you do not need to update immediately - but we strongly recommend purchasing the Orange Book to ensure you are ready for the October 2026 changeover.
Buy your copy of Amendment 4:2026
Protect yourself from dangerous fake copies of BS 7671 and other IET publications by buying your copy from the IET bookshop or one of our trusted resellers.
Alternatively, our Digital Wiring Regulations (DWR) subscription packages provide instant online access to BS 7671 and a wide range of IET guidance.
How updates to BS 7671 are published
Editorial corrections to IET publications are made quarterly. Urgent technical changes are published as and when required.
Check back on this page regularly or subscribe to Wiring Matters for updates.
Note on copyright
No further electronic copying of downloaded updates is permitted without written permission. You may create a web link to this page, from which others can select and download documents. Direct links to documents are not permitted.
Errata and corrections for current publications
Amendment 3:2024 to BS 7671:2018 IET Wiring Regulations (the Brown Book)
Amendment 3:2024, the free-to-download PDF ‘bolt-on’ to the brown book published is now available for free below.
You will now need both the brown book and the free PDF to be up-to-date.
The Brown book, Amendment 2:2022 and the PDF ‘bolt-on’ will be valid until 15 October 2026.
Corrigendum (May 2023) to BS 7671:2018+A2:2022
The Corrigendum (May 2023) to BS 7671:2018+A2:2022 is available to download below.
Previous edition corrections
The following corrections relate to earlier amendments or editions and remain available for reference: