The IET and BSI have confirmed Amendment 4 (2026) to BS 7671:2018 – a major update to the 18th Edition Wiring Regulations that brings new rules for stationary batteries, ICT earthing, Power over Ethernet and medical locations, with BS 7671:2018+A4:2026 set to become the new national standard for low-voltage electrical installations from April 2026.
What is Amendment 4 to BS 7671?
Amendment 4 (2026) is the latest update to BS 7671:2018, the IET Wiring Regulations that underpin electrical safety for design, installation, inspection and testing of low-voltage installations in the UK. It consolidates previous changes (including Amendment 3:2024) into BS 7671:2018+A4:2026 and introduces new requirements driven by energy storage, digital infrastructure and modern healthcare environments.
The amendment is jointly published by the Institution of Engineering and Technology (IET) and BSI, reinforcing BS 7671’s role as the UK’s national standard for all new installations, additions, alterations and periodic inspections. According to the IET, Amendment 4 is described as an “essential update” that the industry must be ready to adopt as current editions are phased out.
Key technical changes in Amendment 4
Amendment 4 brings several headline technical changes that electricians and designers will need to understand and apply in day‑to‑day work.
New chapter on stationary secondary batteries
A completely new chapter deals with stationary secondary batteries used for electrical storage and supply to installations. This reflects rapid growth in technologies such as domestic and commercial battery storage, uninterruptible power supplies, and systems supporting prosumer and low‑carbon installations.
The new section will influence:
- System design and siting of battery systems (ventilation, access, fire and fault protection).
- Integration with existing installations, including protection, isolation and labelling requirements.
- Coordination with renewable generation and backup supplies to maintain safe operation under normal and fault conditions.
For installers already working with EV chargers, PV and home storage, these rules will formalise best practice and help standardise safe battery installations across domestic, commercial and industrial premises.
New section on functional earthing for ICT systems
A new section addresses functional earthing and functional equipotential bonding for ICT equipment and systems, recognising that modern buildings depend on complex data networks, servers and sensitive electronics. The aim is to improve electromagnetic compatibility, reduce interference and provide consistent earthing arrangements for ICT infrastructures.
In practice, this will affect:
Data centres, communication rooms and server spaces with extensive ICT installations.
Office, education, healthcare and industrial environments where ICT and power cabling run in close proximity.
Coordination between electrical and IT design teams to ensure safe, functional and compliant bonding arrangements.
Electricians will need to be more familiar with ICT earthing interfaces, potentially working alongside IT specialists to implement compliant designs.
New section on Power over Ethernet (PoE)
Amendment 4 introduces a dedicated section for Power over Ethernet (PoE), acknowledging its fast-growing role in powering devices such as CCTV cameras, access control, wireless access points and smart building systems via network cabling
The PoE section will clarify:
- How PoE systems interface with the wider electrical installation from a safety and thermal perspective.
- Requirements for cable routing, bundling and installation to manage heating and fire risk when carrying power as well as data.
- Responsibilities at the boundary between traditional electrical circuits and network‑based power delivery.
For contractors, this means closer attention to how structured cabling and electrical systems interact, especially on large commercial jobs and smart home projects.
Major revision of Section 710: Medical locations
Section 710, covering medical locations, is substantially revised, reflecting evolving clinical environments and safety expectations. The amendment introduces a schedule of test results specifically for recording the resistance of supplementary protective equipotential bonding conductors in medical locations.
This tighter focus will impact:
- Hospitals, clinics, dental surgeries and other healthcare premises classified as medical locations.
- Contractors responsible for new projects, refurbishments or periodic inspection and testing in healthcare environments.
- Documentation processes, with more explicit recording of bonding resistance values to demonstrate patient and staff safety.
Those working in healthcare will need to align test procedures and certification with the new schedule once Amendment 4 comes into effect.
Wider updates and harmonisation
Beyond the headline sections, Amendment 4 includes further changes across all parts of BS 7671:2018+A4:2026 and formally incorporates Amendment 3:2024 into the main document. The update continues the UK’s alignment with CENELEC Harmonised Documents and IEC standards, ensuring BS 7671 evolves alongside international best practice and emerging technologies such as prosumer systems and smart grids.
This sustained harmonisation supports:
- Cross‑border consistency of products and design methods.
- Clarity for manufacturers, specifiers and installers working with international equipment.
- Easier navigation of standards for those involved in larger infrastructure or multi‑national projects.
Implementation dates and compliance timelines
Understanding when Amendment 4 applies is as important as understanding what has changed. Amendment 4 is scheduled to be published on 15 April 2026, at which point BS 7671:2018+A4:2026 can be implemented immediately, and from that date the new consolidated standard will be available via the IET’s BS 7671 portal, Get the Regs. According to the IET, Amendment 4 will then be the recognised basis for all new low‑voltage electrical installations, for additions and alterations to existing installations, and for periodic inspection and testing work.
The current consolidated edition, BS 7671:2018+A2:2022+A3:2024, will be withdrawn six months after the publication of Amendment 4, creating a defined transition period during which the industry can familiarise itself with the new requirements and adjust designs, training and certification accordingly. Duty‑holders, designers and contractors should use this window to plan updates to internal procedures, standard designs and specification templates, review how battery storage, ICT, PoE and medical‑location work will be handled under the new rules, and schedule training and qualification updates so electricians are ready to work to the latest standard.
Why Amendment 4 matters for the industry
Amendment 4 is more than a technical tidy‑up; it reflects how real installations are changing as the UK moves towards net zero and more connected buildings.
Supporting net zero and electrification
BSI notes that BS 7671 “underpins safe, modern electrical infrastructure, essential for delivering the electrification needed to meet net zero ambitions” as the UK accelerates towards its 2030 clean energy goals. The new chapter on stationary secondary batteries is a key part of this, providing a structured regulatory basis for energy storage that supports:
- Domestic and commercial PV and battery combinations.
- Load‑shifting, peak shaving and backup power for resilience.
- Integration of low‑carbon technologies across housing, commercial and industrial estates.
For installers, understanding these rules will be critical as clients increasingly seek battery storage, EV infrastructure and smarter energy management solutions.
Embracing emerging technologies and smart infrastructure
The introduction of dedicated sections for ICT functional earthing and PoE reflects a shift towards integrated electrical and digital infrastructures. Modern buildings rely on complex ICT networks and PoE devices for safety, security, communication and building management, and Amendment 4 is designed to ensure these systems are installed safely and consistently.
Electricians who can demonstrate competence in these areas will be well positioned to win work on:
- Smart commercial offices and campuses.
- Education and healthcare builds with high ICT density.
- Smart homes and mixed‑use developments.
Raising safety standards in healthcare
The extensive revision of Section 710 and the new testing schedule for bonding in medical locations emphasise the importance of electrical safety where patients, medical equipment and staff are at higher risk. Hospitals and clinics will expect contractors to work fully in line with the new requirements when carrying out both project work and ongoing inspection and testing.
For contractors operating in the healthcare sector, early engagement with Amendment 4 will be essential to maintain trust with clients, insurers and regulators.
Practical next steps for electricians and duty‑holders
As Amendment 4 approaches, there are clear actions that installers, designers and responsible persons can take now to manage the transition smoothly and stay compliant.
1. Stay informed and get the new book
Keep an eye on official updates from the IET and BSI and note the publication date of 15 April 2026 for BS 7671:2018+A4:2026, then plan to obtain the latest edition of the Wiring Regulations via the IET’s Get the Regs portal or authorised distributors.
2. Review your current and upcoming projects
Review your current workload and identify projects involving battery storage, ICT‑heavy environments, PoE or medical locations where Amendment 4 is likely to have the biggest impact, and for work scheduled beyond the six‑month transition period, assume that designs and certification will need to comply with BS 7671:2018+A4:2026.
3. Update training and competence
Ensure key personnel hold an up‑to‑date 18th Edition qualification and are ready to bridge across to the Amendment 4 requirements as training and guidance become available, and consider scheduling or rescheduling your 18th Edition Wiring Regulations training with Logic4training so that your competence aligns with your business’s regulatory roadmap.
4. Refresh documentation, procedures and templates
Review standard method statements, test sheets and certification templates, particularly for medical locations and battery installations, to align them with the new schedules and data requirements, and check that internal design guides reflect the latest thinking on ICT earthing, PoE and the coordination of protective devices with storage and generation sources.
How Logic4training helps you get Amendment 4‑ready
Logic4training has supported electricians and multi‑discipline installers with BS 7671 from the 17th Edition through to the 18th Edition with Amendment 3, so we are well placed to help the industry transition to Amendment 4. With the new amendment due in April 2026, we see structured training and CPD as essential for staying compliant and competitive, particularly on higher‑risk or more complex installations.
We recognise that an 18th Edition qualification is now widely expected for Registered Electrician status, ECS Gold Cards and Competent Person Scheme membership, so keeping BS 7671 knowledge current is central to credibility with clients and schemes. As BS 7671:2018+A4:2026 becomes the new benchmark, we help electricians demonstrate familiarity with the latest requirements so they can stand out when tendering and show that they can design, install and inspect to the new rules. To support this, we offer in-centre wiring regulations training, plus insight content such as The 18th Edition Wiring Regulations: What You Need to Know, alongside regular blogs that turn regulatory updates into straightforward on‑site guidance.
With over 20 years in the building services training sector and more than 60,000 people trained across gas, electrical, plumbing and renewables, we have a strong track record in delivering accredited, industry‑recognised qualifications. We routinely refresh our course content to reflect changes such as 18th Edition Amendments 2 and 3, ensuring learners are ready for both exams and real‑world compliance, and we will take the same approach as Amendment 4 is introduced into BS 7671. For contractors, electricians and duty‑holders planning ahead for the new Wiring Regulations, we provide a trusted pathway to the knowledge and confidence needed to work to BS 7671:2018+A4:2026 from day one.
Our thoughts
From our point of view, Amendment 4 is a positive and necessary step for the electrical industry. It strengthens safety across areas such as battery storage, ICT systems, PoE and medical locations, and it does so at a time when the UK is accelerating electrification and rolling out more complex, interconnected installations. By tightening requirements and clarifying expectations, the amendment should reduce ambiguity for contractors, improve installation quality and give clients greater confidence in the work being carried out.
The update also aligns BS 7671 more closely with the technologies that electricians are seeing on the ground: domestic and commercial storage, EV infrastructure, smart buildings and digital‑heavy environments. This should help the sector support the UK’s net‑zero and resilience goals while maintaining a clear, common rulebook for everyone involved in design, installation and inspection.
For us, the real opportunity lies in skills. Each amendment raises the bar on competence, and Amendment 4 is no different. It creates a clear case for targeted CPD, structured 18th Edition training and ongoing support so electricians can apply the new rules confidently in practice. By updating our wiring regulations courses, insights and technical guidance in line with BS 7671:2018+A4:2026, we aim to help electricians, contractors and duty‑holders turn this regulatory change into an advantage by using the new standard to differentiate their businesses, protect end users and future‑proof their careers.
FAQs
When does Amendment 4 to BS 7671:2018 come into force?
Amendment 4 is scheduled to be published on 15 April 2026 and can be implemented immediately from that date. The existing consolidated version, BS 7671:2018+A2:2022+A3:2024, will then be withdrawn six months later, after which BS 7671:2018+A4:2026 will be the definitive British Standard for low‑voltage electrical installations, additions and periodic inspection and testing.
What are the main changes in Amendment 4?
Amendment 4 introduces several headline updates, including:
- A new chapter on stationary secondary batteries for electrical storage and supply.
- New requirements for functional earthing and bonding for ICT systems.
- A dedicated section on Power over Ethernet (PoE) and cabling carrying both data and power.
- A major revision of Section 710: Medical locations, including a new schedule for recording bonding resistance.
It also incorporates Amendment 3:2024 into a single consolidated document and continues the UK’s alignment with CENELEC and IEC standards.
Will Amendment 4 be mandatory straight away?
No. There is a transition period.b From 15 April 2026, installations can comply with either BS 7671:2018+A2:2022+A3:2024 or BS 7671:2018+A4:2026. Six months after publication, the earlier consolidated edition will be withdrawn, and BS 7671:2018+A4:2026 will be the national standard referenced by schemes and clients.
Duty‑holders should plan to move to Amendment 4 as early as practical within this window.
Do electricians need to retake their 18th Edition exam for Amendment 4?
If you already hold an 18th Edition (2382) qualification, you are not automatically forced to retake the full course when a new amendment appears, but you do need to update your knowledge. Certification bodies and clients are likely to expect evidence of CPD or amendment‑specific training showing that you understand the new requirements, particularly around batteries, ICT, PoE and medical locations.
Logic4training will reflect Amendment 4 in its 18th Edition training and update pathways, helping candidates bridge from earlier versions of BS 7671 to the 2018+A4:2026 standard.
How does Amendment 4 affect battery storage and renewable installations?
Amendment 4 introduces a new chapter on stationary secondary batteries, covering design, siting, protection and integration of battery systems. This is particularly relevant for:
- Domestic and commercial PV‑plus‑battery systems.
- UPS and backup systems for critical loads.
- Prosumer and low‑carbon installations that import/export energy.
The new rules formalise best practice on ventilation, access, fire protection, fault protection and coordination with other sources, so installers working with EV chargers, PV and storage will need to align their designs and documentation with the new chapter.
Why are ICT earthing and Power over Ethernet included in the Wiring Regulations?
Modern buildings rely on ICT networks and PoE devices for safety, security, communication and control, and these systems interact closely with the electrical installation. Amendment 4 introduces:
- A section on functional earthing and equipotential bonding for ICT systems, aimed at EMC performance and safe operation.
- A section on PoE, clarifying how power‑carrying data cabling should be installed, rated and protected.
This ensures that structured cabling, network switches and powered devices are treated with the same level of electrical safety and design discipline as conventional LV circuits.
What changes are made for medical locations (Section 710)?
Section 710 is substantially revised to reflect current healthcare practice and risk levels. Key points include:
- A new schedule of test results for recording the resistance of supplementary protective equipotential bonding conductors.
- Clearer expectations for documentation to demonstrate ongoing safety for patients, staff and visitors.
Hospitals, clinics and other medical locations will expect contractors to adopt the new test schedules and reporting formats as part of their inspection and maintenance regimes.
How long do I have to switch my designs and paperwork to Amendment 4?
You have six months from the date of publication to move from BS 7671:2018+A2:2022+A3:2024 to BS 7671:2018+A4:2026. During this transition period, you should update your standard designs, specifications and method statements, refresh inspection and testing forms (particularly for medical locations and battery installations), and plan and deliver training so that staff are comfortable working to the new edition.
How will Amendment 4 support net zero and future technologies?
BSI and the IET emphasise that Amendment 4 underpins safe, modern electrical infrastructure, which is essential to deliver electrification and support the UK’s net zero ambitions. The new and revised sections are designed to enable the safe deployment of battery storage and other low‑carbon technologies, support smart buildings, digital infrastructure and integrated power/data systems, and maintain safety and resilience in critical environments such as medical locations. Together, these developments help ensure BS 7671 keeps pace with evolving technologies while remaining aligned with European and international standards.
Your latest offers & alerts