BS 7671 Amendment 4 (2026): What Electricians Need to Know

BS 7671:2018+A4:2026 was published on 15 April 2026, marking the latest update to the IET Wiring Regulations (18th Edition). This is the second full consolidated amendment and introduces significant changes that every UK electrician needs to understand. Whether you work in domestic installations, commercial properties, or specialist environments such as medical locations, Amendment 4 to the 18th Edition wiring regulations will affect how you design, install, inspect, and certify electrical work.

Here is everything you need to know about BS 7671 Amendment 4: the key changes, the new rules on battery storage regulations under BS 7671, the EICR qualification changes for 2026, and the deadlines you must not miss.

When Does Amendment 4 Come Into Force?

Understanding the Amendment 4 timeline is essential for planning your work and ensuring compliance with the updated wiring regulations. BS 7671 Amendment 4 2026 follows a phased introduction, giving electricians time to familiarise themselves with the changes before the current edition is officially withdrawn.

The six month overlap period between publication and withdrawal is standard practice for amendments to the wiring regulations. It gives you time to obtain the updated regulations, attend any necessary training, and adjust your working practices. However, there is nothing stopping you from working to the new standard straight away.

It is worth noting that existing installations do not need to be retrospectively upgraded to meet Amendment 4 requirements. The new rules apply to new installations, additions, and alterations carried out after the October 2026 deadline. However, if you are carrying out an EICR on an existing installation, you should be aware of the updated requirements so that you can advise your clients accurately.

1. Stationary Secondary Batteries (New Chapter)

One of the most significant additions in the 18th Edition Amendment 4 is a completely new chapter covering stationary secondary battery systems. With the rapid growth of domestic solar panels and home battery storage installations across the UK, this new chapter fills a critical safety gap that the industry has been calling for.

The new battery storage regulations in BS 7671 cover several important areas:

• Thermal runaway mitigation: New requirements for preventing and managing thermal runaway events in battery systems. This includes specifications for ventilation, fire detection, and containment measures around battery installations.
• Isolation procedures: Specific procedures for safely isolating battery systems during maintenance and emergency situations. Battery systems present unique hazards because they cannot simply be switched off in the same way as a mains supply.
• Location restrictions: Batteries are now prohibited from being installed in lofts, escape routes, and other high risk areas in domestic properties. This addresses growing concerns about the fire risk posed by lithium ion batteries in enclosed or difficult to access spaces.
• Installation requirements: Detailed guidance on cable sizing, protection, and labelling for battery storage circuits, ensuring they are clearly identified and properly protected.

If you are already working on solar and battery storage installations, you should study this new chapter thoroughly before the Amendment 4 deadline in October 2026. The requirements are detailed and represent a significant addition to the knowledge you need for compliant installations.

2. ICT Systems and Power over Ethernet

Amendment 4 to the wiring regulations introduces a new section addressing information and communication technology (ICT) systems and Power over Ethernet (PoE). This reflects the reality that modern electrical installations increasingly involve data infrastructure alongside traditional power circuits.

The key additions include:

• Functional earthing for ICT equipment: New guidance on how to properly earth networking equipment, servers, and data cabinets. Functional earthing for ICT systems is different from protective earthing and requires specific attention during installation.
• Equipotential bonding for data infrastructure: Requirements for maintaining equipotential bonding where ICT equipment is connected to the electrical installation. This is particularly important in commercial environments with large data networks.
• Power over Ethernet regulations: PoE technology allows data cables to carry both data and power. With the growth of smart building systems, security cameras, wireless access points, and LED lighting powered via PoE, these systems now have specific regulations under BS 7671.
• Smart home technology: The amendment addresses modern smart home installations where lighting, security, heating, and entertainment systems may be powered or controlled through data cables rather than traditional mains wiring.

For electricians working on commercial fit outs, office refurbishments, or modern domestic installations, the ICT provisions in Amendment 4 provide important clarity on responsibilities and requirements. The boundary between IT infrastructure and electrical installation has been blurring for years, and these new rules help define where your obligations lie.

3. Medical Locations (Section 710 Revision)

Section 710 of BS 7671, covering medical locations, has received a major revision in Amendment 4. Healthcare environments have some of the most demanding electrical requirements of any building type, and this update brings the regulations in line with current practice and technology.

The key changes include:

• New schedule of test results: A new standardised format for recording supplementary protective equipotential bonding conductor resistance test results in medical locations. This makes it easier to document compliance and compare results across different sites and inspections.
• Updated classification of medical locations: More detailed requirements for different groups of medical locations, reflecting the variety of healthcare environments from GP surgeries to operating theatres.
• Emergency power supply requirements: Revised guidance on changeover times and the classification of essential services that require backup power.
• IT power distribution systems: Updated requirements for IT (isolated terra) power distribution systems used in critical care areas, including monitoring and alarm requirements.

If you work in healthcare environments, the Section 710 changes in Amendment 4 are essential reading. Medical location electrical work is already a specialist area, and these updates raise the bar further. Make sure you are familiar with the new test result schedules before the October 2026 deadline.

4. EICR Qualification Changes (Critical Deadline)

For many working electricians, the EICR qualification changes in 2026 will be the most immediately impactful element of Amendment 4. The changes to qualification requirements have been coming for some time, and the deadline is now firm.

Here is what the EICR qualification changes mean in practice:

• Mandatory Level 3 qualifications: Individual electricians carrying out inspection and testing work must hold the appropriate Level 3 Award in the Inspection, Testing, and Certification of Electrical Installations (or equivalent).
• End of the experience route: Previously, electricians with sufficient documented experience could carry out EICR inspections without holding a specific qualification. That route is closing permanently on 1 October 2026.
• Design certification: Similar requirements apply to those certifying electrical design work. You must hold the relevant qualification, not just demonstrate experience.
• Competent person schemes: If you are registered with a competent person scheme, check with your scheme provider about any additional requirements or transitional arrangements.

If you have been working on the experience route, you need to act now. Training courses are likely to fill up quickly as the October 2026 deadline approaches, and the last thing you want is to find yourself unable to carry out EICR inspections because you could not book onto a course in time.

The EICR qualification changes are separate from the technical changes in Amendment 4, but the timing means that electricians face a double requirement: update your knowledge of the new regulations and ensure your formal qualifications are in order, both before October 2026.

5. Surge Protection (Updated Requirements)

Amendment 4 includes updated guidance on surge protection device (SPD) requirements, building on the changes introduced in earlier amendments. Surge protection has become increasingly important as homes and businesses rely more heavily on sensitive electronic equipment.

The updated requirements include:

• Clarified mandatory circumstances: Amendment 4 provides clearer guidance on when SPDs are mandatory rather than recommended. This reduces ambiguity and makes it easier for electricians to determine the correct specification for each installation.
• Smart device considerations: With the growth of smart home systems, connected appliances, and IoT devices, the risk from transient overvoltages has increased. The updated surge protection requirements reflect this evolving risk landscape.
• Selection guidance: Improved guidance on selecting the appropriate type and rating of SPD for different installation types and risk levels.
• Coordination with other protective devices: Updated information on coordinating SPDs with RCDs and MCBs to ensure that the overall protection system works effectively.

Surge protection is an area where the Amendment 4 changes build on a trend that has been developing across recent editions of BS 7671. If you have not yet made SPDs a standard part of your specifications for new installations, now is the time to start.

6. EV Charging (Continued Development)

Section 722 of BS 7671, covering electric vehicle charging installations, receives further refinements in Amendment 4. With the UK government's commitment to phasing out new petrol and diesel cars, and the continued expansion of the public and private EV charging network, these updates are timely.

The Amendment 4 changes to EV charging regulations include:

• Updated installation requirements: Refinements to the technical requirements for EV charging circuits, including cable sizing, protection, and labelling requirements.
• Alignment with Building Regulations: Better alignment between BS 7671 and the Building Regulations requirements for EV charging infrastructure in new buildings and major renovations.
• Public charging considerations: Additional guidance for installations in publicly accessible locations, including car parks, workplaces, and on street charging points.
• Load management: Updated guidance on load management systems for multiple charger installations, reflecting the increasing number of sites with several charging points.

If EV charging installations form a significant part of your workload, review the Section 722 changes carefully. The EV charging market is growing rapidly, and staying current with the latest BS 7671 requirements is essential for winning and completing work in this sector.

What You Need to Do Now

With the Amendment 4 deadline set for October 2026, you have six months to prepare. Here is a practical checklist for electricians and contractors to ensure you are ready for BS 7671 Amendment 4.

1. Order or download the updated regulations. The full text of BS 7671:2018+A4:2026 is available from the IET and BSI. Do not rely on summaries alone. You need to read the actual regulation text for the areas relevant to your work.
2. Complete any required qualifications. If you carry out EICR inspections or design certification, confirm that you hold the appropriate Level 3 qualifications. If not, book your training course now before demand peaks.
3. Attend training or CPD events. Many training providers and industry bodies are running events on Amendment 4 changes. These are valuable for understanding the practical implications of the new rules.
4. Review your standard specifications. If you use template specifications or standard designs, update them to reflect Amendment 4 requirements, particularly around surge protection, battery storage, and ICT systems.
5. Update your certificate software. Make sure your digital certificate tools reflect the current standard reference. Certificates issued after October 2026 should reference BS 7671:2018+A4:2026.
6. Brief your team. If you employ or subcontract other electricians, make sure everyone is aware of the changes and the deadlines.

How LedgerCert Helps

LedgerCert is a free web app for UK electricians and fire safety engineers to create, manage, and export digital compliance certificates. As BS 7671 Amendment 4 comes into effect, LedgerCert is being updated to reflect the new requirements across all relevant certificate types.

LedgerCert already supports EICR, EIC, Minor Works Certificates, Emergency Lighting certificates, Fire Alarm certificates, and EV charging certificates. All certificates are built to include the mandatory fields required by the relevant British Standards, and the observation codes and classification systems used in EICRs follow the current standard.

As the Amendment 4 requirements take effect, LedgerCert will be updated to reference BS 7671:2018+A4:2026 and incorporate any changes to certificate formats, test schedules, or reporting requirements. If you are looking for a simple, compliant way to create digital certificates, you can get started for free today.