Overview of the 2026 Wiring Regulation Updates
The IET and BSI have confirmed the publication of Amendment 4:2026 to BS 7671:2018, bringing the 18th Edition Wiring Regulations fully up to speed with the rapid pace of modern electrical technology. From battery energy storage to smart building systems and Power over Ethernet, these updates ensure UK standards remain safe, practical, and aligned with harmonised European requirements.
For electricians, designers, and engineers, this isn’t a complete rewrite, but it is a crucial technical evolution that will directly affect how installations are designed, tested, and maintained. So, what does that mean for you? Keep reading to find out the key updates and how this changes our 18th Edition training courses, and how to keep your skills up-to-date.
What Has Changed with Amendment 4?
1. New Requirements for Stationary Secondary Batteries
With battery energy storage systems (BESS) becoming increasingly common in UK homes, commercial buildings, and renewable installations, Amendment 4 introduces a dedicated chapter defining safe installation and operation requirements.
- Standardised Installation: Provides a clear framework for backup power and advanced energy management systems.
- Safety & Compliance: New requirements for siting, protection, and integration help ensure systems are future-ready and safe.
2. Functional Earthing & Bonding for ICT Equipment
As ICT and smart technologies continue to expand, the regulations now include a new section detailing functional earthing and equipotential bonding for communication and data systems.
- Maintaining Integrity: Modern setups, from data centres to smart building networks, rely on stable earthing to prevent interference.
- Reducing Risk: These new rules mitigate electromagnetic disturbances and potential differences that could damage sensitive equipment.
3. Dedicated Section for Power over Ethernet (PoE)
PoE is rapidly growing across smart buildings, security systems, and digital devices. Amendment 4 provides clearer guidance on safe PoE design and installation.
- Power & Data Integration: PoE allows both data and electrical power to be delivered over the same cable, powering cameras and smart sensors.
- Thermal Management: As power levels increase, electricians must manage heat build-up and cable ratings to ensure safety.
4. Major Revision to Section 710: Medical Locations
Healthcare environments require extremely precise electrical safety standards. A full update to Section 710 includes new testing schedules for supplementary protective bonding resistance.
- Critical Resilience: Changes introduce clearer requirements for earthing, bonding, and supply continuity to protect patients on life-support equipment.
- Safety Standard Alignment: These updates align UK facilities with the latest safety standards for modern healthcare technology.
Critical Dates for Implementation
To remain compliant, you must be aware of the following timeline:
- Publication Date: 15 April 2026.
- Implementation Date: Immediately effective from 15 April 2026.
- Withdrawal of Previous Version: The current version (BS 7671:2018+A2:2022+A3:2024) will be withdrawn on 15 October 2026.
- Transition Period: There is a six-month window where both versions are valid, allowing time to complete designs started under the previous amendment.
Who Must Use the New Regulations?
Amendment 4 applies to:
- All new low‑voltage electrical installations
- Additions and alterations to existing installations
- Periodic inspection and testing of electrical systems
This means virtually every practising electrician, inspector, or contractor will need to know and work to the updated standard once it’s in force.
Training Requirements
As Amendment 4 is introduced, training and professional competency will become even more important for electricians and engineers. While much of the existing knowledge remains relevant, the new and revised sections mean that both training programmes and individual skill sets will need to adapt to reflect the latest requirements of BS 7671.
Training & Courses
We will be updating our 18th Edition courses to include Amendment 4 content from April 2026.
Keep checking for new qualification tracks that may be launched that align directly with Amendment 4 requirements.
Skills & Competency Updates
Electricians and engineers should prepare to:
- Study updated sections on batteries, PoE, ICT earthing, and medical locations
- Revise typical installation practices to align with new requirements
- Update testing and inspection templates where necessary
Order Your Copy of the New Regs
It is advised to have the official documentation ready for the April launch. You can secure your copy of the new regulations now.
Order now at: www.tester.co.uk
Amendment 4 FAQs
Not necessarily. Many electricians will be able to update their knowledge through Amendment 4 update or refresher training, rather than retaking the full qualification. The right option depends on your experience and how recently you completed your 18th Edition training.
As soon as the new regulations are published in April 2026 our 18th Edition courses will be updated to include Amendment 4 content . This means you’ll be learning the latest requirements and how they affect real-world installations, testing, and compliance practices.
We’ll also be offering stand-alone Amendment 4 update sessions specifically designed for electricians who already hold an 18th Edition qualification and want to bring their skills fully up to date with the new regulations.
Your existing qualification remains valid, but you will need to understand and apply the new Amendment 4 requirements to remain compliant when carrying out work under the updated regulations.
Until 15 October 2026, installations can be designed to BS 7671:2018+A2:2022+A3:2024.
Electrical installations should be inspected against the regulations applicable at the time they were installed, although the latest updates will inform future inspection and testing practices.
Further Information
Still unsure which training route is right for you with the introduction of Amendment 4? Our team is here to guide you through the options and help you stay compliant and confident. Please don’t hesitate to contact our Training team.
