BSI published BS 7671:2018+A4:2026, the latest amendment to the IET Wiring Regulations, on 15 April 20261. The standard is described by BSI as the UK's national standard for the design, erection and verification of electrical installations, covering installations at voltages up to 1000V AC and 1500V DC1. It supersedes BS 7671:2018+A2:2022+A3:2024, which will be officially withdrawn on 15 October 2026 but remains valid for six months after Amendment 4's April 2026 release1.
Amendment 4 introduces a new chapter on stationary secondary batteries for electrical storage and supply, a new section on functional earthing and equipotential bonding for ICT equipment and systems, and a new section on Power over Ethernet1. It also carries a major revision of Section 710 on medical locations, including new requirements for recording the resistance of supplementary protective equipotential bonding conductors, and incorporates Amendment 3:2024 into the main document1. BSI states that BS 7671 is the most widely accepted way to demonstrate compliance with UK electrical safety legislation, namely the Electricity at Work Regulations 19891.
"BS 7671:2018+A4:2026 supersedes BS 7671:2018+A2:2022+A3:2024, which will be officially withdrawn on 15 October 2026 but remains valid for six months after Amendment 4's April 2026's release."
The new battery chapter sits alongside separate standards for home storage. The standards governing home battery installation, including PAS 63100 and MIS 3012, are not covered in the BSI publication notice, and no detail on how the new chapter interacts with them has been reported1.
A second source, an installer-facing guide published on 25 April 2026, states that Amendment 4 becomes mandatory from 15 October 2026 and that all EV charger installations must comply with BS 76712. It also sets out the current shape of the OZEV EV Chargepoint Grant, which it says is primarily for eligible renters, flat owners and residential landlords as of April 2026, with homeowners of single-unit properties with off-street parking generally no longer eligible unless they have on-street parking and permission for a cross-pavement solution2.
| Grant route | Maximum support stated |
|---|---|
| Renters and flat owners | Up to £500 towards charger and installation2 |
| Households with on-street parking | Up to £5002 |
| Landlords | Up to £500 per socket, maximum 200 sockets across all sites2 |
The same guide states that a 7kW smart charger is a practical choice for most UK homes, compatible with typical domestic single-phase supplies, and that each charger must be on a dedicated circuit from the consumer unit with appropriate protection against electric shock2. It adds that most homeowners in England do not need planning permission for a wall-mounted charge point under permitted development rights, provided the unit is under 0.2 cubic metres and the property is not a listed building or scheduled monument2.
Why it matters for households
BS 7671 is the document an electrician works to when wiring a consumer unit, a solar inverter, a home battery or a charge point, and it is the reference used to demonstrate compliance with electrical safety law1. A new chapter on stationary secondary batteries means domestic storage now has dedicated wiring requirements within the national standard rather than being handled by analogy with other equipment1. For a household adding storage, that shapes what an installer must design, verify and certify. The electrical safety regulation framework, including Part P, sits alongside the standard, and the guide to what changed in Amendment 4 covers the amendment in more detail. Households considering backup power should note that the safety and standards position for such equipment is not addressed in the publication notice1.
What happens next
BS 7671:2018+A2:2022+A3:2024 remains valid until 15 October 2026, when it is officially withdrawn1. From that date, the installer-facing guide states Amendment 4 is mandatory2. No further transitional arrangements beyond the six-month overlap have been reported1.
Sources2 cited
- BS 7671:2018+A4:2026 - SET | 15 Apr 2026 | BSI Knowledge, knowledge.bsigroup.com
- Home EV charger installation costs, fuseenergy.com