BS7671 18th Edition Amendment 4

The IET and BSI have confirmed that Amendment 4 (2026) to BS 7671:2018 (18th Edition Wiring Regulations) will be published on 15 April 2026.

From the date of publication, Amendment 4 can be implemented immediately. The current standard, BS 7671:2018 + A2:2022 + A3:2024, will remain in force for a six-month transition period, after which it will be withdrawn.

Once the transition period ends, Amendment 4 will become the required standard for:

• All new low-voltage electrical installations

• Alterations and additions to existing installations

• Periodic inspection, testing, and EICR reporting

Key Technical Changes Electricians Should Be Aware Of

Amendment 4 introduces several important updates that will directly affect installation, inspection, and certification practices:

• New chapter covering stationary secondary batteries, specifically where batteries are used for electrical energy storage and supply to installations

• New requirements for functional earthing and functional equipotential bonding for information and communication technology (ICT) equipment and systems

• Introduction of a dedicated section on Power over Ethernet (PoE), reflecting the increased use of PoE in modern installations

• Major revision of Section 710 (Medical Locations), including a new schedule of test results for recording the resistance of supplementary protective equipotential bonding conductors

What Contractors Need to Do

• Ensure access to the latest version of BS 7671, including Amendment 4

• Review design, installation, and inspection procedures affected by the new sections

• Update testing and certification documentation where required

• Apply professional judgement in line with the revised requirements, particularly during EICRs

Amendment 4 can be adopted immediately from 15 April 2026. Contractors are advised to familiarise themselves with the changes early to ensure continued compliance with scheme rules and best practice.