BS 7671:2018+A4:2026 — What Changed and What To Do
BS 7671:2018+A4:2026 is the latest amendment to the UK’s IET Wiring Regulations, introducing new chapters on stationary batteries, ICT earthing, Power over Ethernet and a major revision of medical location requirements.
What is BS 7671:2018+A4:2026?
BS 7671:2018+A4:2026 is the UK’s national standard for the design, erection and verification of electrical installations, also known as the IET Wiring Regulations. It applies to electrical professionals including designers, contractors, installers, inspectors, testers and specifiers working in domestic, commercial and specialised environments such as swimming pools, highways and solar photovoltaic systems. This amendment introduces essential updates to reflect new technologies, emerging risks and the UK’s clean energy goals.
What changed?
- A new chapter on stationary secondary batteries – addresses requirements for electrical storage systems that support renewable energy integration and grid resilience.
- A new section on functional earthing and equipotential bonding for ICT equipment and systems – provides clear rules for safety and performance as information technology becomes integral to buildings.
- A new section on Power over Ethernet (PoE) – sets requirements for safely and reliably powering devices via data cables, supporting smart buildings and IoT.
- A major revision of requirements for medical locations – includes enhanced provisions and a new schedule of test results for recording the resistance of supplementary protective equipotential bonding conductors.
- Incorporation of Amendment 3:2024 – integrates previous updates to ensure consistency and clarity across the standard.
- Further adoption of CENELEC Harmonized Documents and IEC standards – aligns the regulations with European and international standards, supporting trade and innovation.
Key dates and facts
| Published | 15 April 2026 |
| Supersedes | BS 7671:2018+A2:2022+A3:2024 |
| Previous edition withdrawn | 15 October 2026 – confirm with your certification body for transitional arrangements |
| Certifiable | Yes – requirements standard |
What should you do?
- Review your design and installation procedures for electrical energy storage systems to ensure they align with the new chapter on stationary secondary batteries.
- Update your earthing and bonding specifications for ICT installations to incorporate the new requirements for functional earthing and equipotential bonding.
- Revise your Power over Ethernet installation guidance to reflect the new section, including cable selection and safety checks.
- Check your medical location inspection and testing records – introduce the new schedule of test results for supplementary protective equipotential bonding conductors.
- Verify that your compliance documentation and contractual references cite BS 7671:2018+A4:2026, and plan to transition any ongoing projects before the previous edition is withdrawn.
This summary is provided for information only and does not constitute professional or compliance advice. Verify against the published standard. ITMAD accepts no liability for any action taken in reliance on it.