The 18th Edition Wiring Regulations, officially known as BS 7671:2018+A3:2024, set the benchmark for electrical safety in the UK. The 18th edition wiring regulations are essential for electricians, as well as related trades (gas and heating engineers, kitchen fitters and plumbers) who wire in electrical appliances, for example, showers or cookers. In this post, we’ll explore the key aspects of the regulations, recent updates with the new amendment 4:2026, why staying compliant is critical and answer some of your most frequently asked questions.
What Are the 18th Edition Wiring Regulations?
The 18th Edition Wiring Regulations, published by the Institution of Engineering and Technology (IET), provide guidelines on designing, installing, and maintaining electrical installations in compliance with UK standards. They apply to all types of installations, including domestic, commercial, and industrial properties.
The regulations aim to:
- Ensure electrical safety.
- Standardise practices across the industry.
- Incorporate new technologies and innovations.
The 18th Edition contains regulations covering the specification, design, installation and inspection, testing and verification of electrical installations in domestic and commercial buildings, including:
- Part 1: Scope, Object and Fundamental Principles
- Part 2: Definitions
- Part 3: Assessment of General Characteristics
- Part 4: Protection for Safety
- Part 5: Selection and Erection of Equipment
- Part 6: Inspection and Testing
- Part 7: Special Installations or Locations
18th Edition Wiring Regulations Amendments Overview
Since BS 7671:2018 was first published, four amendments have updated the 18th Edition Wiring Regulations to keep pace with emerging technologies, safety expectations and modern installation practices.
| Amendment | Key Changes | Details |
|---|---|---|
| A1:2020: Electric vehicle (EV) charging | Focused update to Section 722 on EV charging installations, reflecting rapid growth in EVs and the need for clearer, more practical safety requirements. | Introduced revised rules for PME (TN-C-S) earthing arrangements, expanded options for open PEN fault detection, clarified RCD selection and protective measures, and made the original 2018 EV requirements less restrictive while maintaining safety for domestic and commercial charge points. |
| A2:2022: Major technical revision | Comprehensive overhaul of BS 7671:2018 including new requirements for prosumer’s low-voltage installations, changes to surge protection, AFDD use, fire safety measures, and updated model forms and terminology. | Brought in Chapter 82 on prosumer installations (including storage and embedded generation), strengthened requirements for RCDs and AFDDs in certain premises, revised special locations (such as Section 722 for EVs), and updated protective devices, labelling and documentation to improve safety, energy efficiency and clarity for designers and installers. |
| A3:2024: Further updates and clarifications | Targeted updates to keep the 18th Edition aligned with evolving technologies and international standards, refining requirements introduced in A2 and clarifying inspection, testing and documentation expectations. | Included refinements to certain special locations and appendices, clearer guidance on coding and reporting in inspection and testing, and adjustments to coordination between protective devices and wiring systems, helping electricians apply the regulations more consistently on real-world projects. |
| A4:2026: New technologies & consolidation | Introduces new chapters and sections for stationary battery systems, ICT earthing and Power over Ethernet (PoE), significantly revises medical locations, and consolidates all previous amendments into BS 7671:2018+A4:2026. | Adds a new chapter on stationary secondary batteries used for energy storage, a new section on functional earthing and equipotential bonding for ICT systems, and a new section on PoE distribution over structured cabling makes major changes to Section 710 (medical locations), updates appendices for more accurate cable rating and voltage drop data, and sets new expectations and timelines for using the “Orange Book” version of the 18th Edition from April 2026 onwards. |
Together, these amendments ensure that BS 7671:2018+A4:2026 remains the definitive standard for modern low-voltage electrical installations in the UK, covering everything from EV charging and prosumer systems to ICT networks, battery storage and medical facilities.
What’s New in the 18th Edition Regulations Amendment 4:2026?
Amendment 4:2026 to BS 7671 builds on the 18th Edition Wiring Regulations by tightening requirements around emerging technologies and high‑risk environments, rather than replacing the 18th Edition altogether. For working electricians, designers and duty‑holders, the key changes focus on battery storage systems, ICT and PoE cabling, medical locations, energy efficiency and updated certification, all of which you now need to understand to stay compliant and competitive on UK jobs after the A4 transition period.
| Area of change | Key changes in Amendment 4:2026 | Details |
|---|---|---|
| New Chapter 57: Stationary secondary batteries | New chapter covering stationary secondary battery systems used for electrical energy storage and supply in low-voltage installations. | Sets out design, installation, protection and ventilation requirements for battery energy storage systems (BESS), including siting, fire and fault protection, integration with prosumer installations and coordination with inverters and control gear. |
| New Section 545: Functional earthing for ICT | Introduces a new section on functional earthing and functional equipotential bonding for information and communication technology (ICT) equipment and systems. | Clarifies separation between protective earthing and functional earthing, gives rules for bonding ICT racks, cabinets and metallic pathways, and helps ensure EMC performance and signal integrity without compromising electrical safety. |
| New Section 716: Power over Ethernet (PoE) | Adds a new section for the distribution of extra‑low‑voltage DC power using structured cabling systems (PoE and similar technologies). | Covers current‑carrying capacity of data cables, bundling and installation methods, temperature rise, separation from higher‑voltage circuits and disconnection/isolation requirements to keep PoE systems safe and reliable. |
| Major revision of Section 710: Medical locations | Substantial rewrite of requirements for medical locations, including new testing and documentation provisions. | Updates rules for medical IT systems, isolation transformers, insulation monitoring devices and supplementary equipotential bonding; introduces a new schedule of test results to record resistance of supplementary bonding conductors, strengthening verification and ongoing safety in clinical environments. |
| Energy efficiency and functional aspects | Enhances guidance on energy efficiency and functional performance of installations, building on Part 8. | Introduces Chapter 81 on functional aspects and energy efficiency, encouraging designers to consider load management, control, monitoring and optimisation measures within compliant low‑voltage installations. |
| Conductor routing and ferromagnetic enclosures | Clarifies requirements for conductors installed in ferromagnetic enclosures to address electromagnetic effects. | Revises Regulation 521.5.1 to reduce risks such as excessive heating or forces under fault conditions, ensuring cables in steel trunking, conduit and similar systems are installed so that magnetic effects are minimised. |
| Isolation and switching requirements | Updates and rationalises some isolation and switching rules. | Deletes Regulation 537.4.2.1 and revises Regulation 537.4.4 for clarity, helping installers apply consistent, clear arrangements for functional switching and emergency control. |
| Inspection, testing and certification | Updates certificates, reports and model forms to align with Amendment 4. | All digital and paper certificates will be brought into line with BS 7671:2018+A4:2026, including new guidance notes and a model form for recording resistance of supplementary bonding in medical locations, plus updated wording and coding guidance in Appendix 6. |
| Appendices: cable data and design info | Revises and extends data used for design calculations in several appendices. | Adds new data for buried cables in ducts and refines current‑carrying capacities and voltage‑drop figures for specific installation conditions, helping designers size conductors more accurately for modern applications. |
| Consolidation of BS 7671:2018+A4:2026 | Consolidates all previous amendments (A1, A2 and A3) into a single “Orange Book” edition. | BS 7671:2018+A4:2026 becomes the new national standard from 15 April 2026, with a six‑month transition period before BS 7671:2018+A2:2022+A3:2024 is withdrawn; designers, electricians and training providers are expected to work to the consolidated edition after October 2026. |
In practice, Amendment 4:2026 makes the 18th Edition Wiring Regulations more closely aligned with how modern UK installations are actually designed, installed, and tested, from domestic renewables and EV infrastructure to data‑heavy commercial buildings and clinical environments. By getting up to speed on BS 7671:2018+A4:2026 now and refreshing your 18th Edition knowledge through structured training with Logic4training, you can demonstrate competence to scheme providers and clients, protect your business against non‑compliance, and open up higher‑value work across the South East and beyond.
For a more detailed summary, visit theIET.
Why Do the 18th Edition Wiring Regulations Matter?
The 18th Edition Wiring Regulations underpin almost everything a modern electrician does, from small domestic jobs through to large commercial and industrial projects. Understanding why these regulations matter, not just what the individual clauses say, helps you make better design decisions, protect your customers and safeguard your business in a rapidly changing electrical landscape.
Legal Compliance
Working to the 18th Edition Wiring Regulations (BS 7671) is one of the clearest ways an electrical business can demonstrate that its work meets the standards expected by UK health and safety law and the Electricity at Work Regulations.
Non‑compliance can expose contractors and duty‑holders to enforcement action, fines and, in the worst cases, prosecution if unsafe work leads to injury, fire or damage. Insurers, scheme providers and commercial clients increasingly expect evidence that work has been designed, installed and certified in line with the latest version of BS 7671, so keeping your 18th Edition knowledge up to date is essential for winning and retaining work as well as protecting your business.
Enhanced Safety
The 18th Edition Wiring Regulations translate complex electrical engineering principles into practical rules that reduce the risk of electric shock, fire and equipment failure in real‑world installations. Requirements around protective devices, RCDs, AFDDs, cable selection, earthing and bonding are all aimed at limiting fault currents, disconnecting dangerous circuits quickly and minimising the chance of faults developing in the first place.
For higher‑risk environments such as residential care homes, HMOs, medical locations and premises with flammable materials. These measures can be the difference between a minor incident and a serious fire or injury, giving duty‑holders greater confidence that their installations are robust and properly documented.
Future-Proofing Electrical Systems
Modern electrical installations are no longer just about supplying sockets and lights; they are at the heart of low‑carbon technologies, smart controls and increasingly complex building services. The 18th Edition has evolved to cover prosumer’s low‑voltage installations, embedded generation, EV charging, battery storage and data‑heavy systems, helping electricians integrate these technologies safely into new and existing properties.
By following the latest requirements for coordinating protective devices, cable sizing, load management, and special locations, installers can design systems that are easier to adapt, extend, and maintain over time, thereby protecting clients’ investments and keeping installations aligned with future updates to standards and technology.
By treating the 18th Edition as a practical framework rather than a tick‑box exercise, electricians can deliver safer, more resilient and future‑ready installations for homes and businesses across the UK. Investing time in keeping your knowledge up to date pays off in fewer call‑backs, smoother inspections, stronger relationships with clients and a real competitive edge as regulations and technologies continue to evolve.
Who Needs to Be Compliant?
The 18th Edition is crucial for:
- Electricians: To carry out compliant installations and stay competitive.
- Contractors: For managing projects safely and adhering to standards.
- Designers: Ensuring new builds are future-proof and energy-efficient.
Other tradespeople like plumbers and kitchen fitters can benefit from completing an 18th Edition Wiring Regulations Training Course. This is because they will often work with electrical appliances.
Do all electricians need to complete an 18th Edition course?
All electrotechnical workers in the UK must work to the standards set out in the 18th Edition of the Wiring Regulations. Completing an 18th Edition course is the best way to achieve compliance.
Training is highly recommended to ensure a thorough understanding, particularly following the release of a new edition, and is required to join a recognised Competent Person Scheme (CPS) and apply for an ECS card. Most companies require 18th Edition training as a pre-requisite to securing work.
Electricians are not expected to memorise the big book, but they should be familiar with key regulations and should always carry a copy with them.
How much does the 18th Edition course cost?
The standard price of 18th Edition training is £485 + VAT and is available at our training centres across the South-East, in Northolt, Luton, Basildon and Sittingbourne.You can find more information on our 18th Edition Wiring Regulations Training Course here.
Key Takeaways for Professionals
- Stay Updated: Regularly review amendments to the regulations.
- Invest in Training: Completing an 18th Edition course is essential for career progression.
- Adapt to Change: Embrace new technologies and practices like prosumer systems and energy efficiency measures.
- Focus on Safety: Prioritise installations that reduce hazards and enhance protection.
Conclusion
The 18th Edition Wiring Regulations are the framework that underpins safe, efficient and commercially viable electrical work in the UK. By understanding and applying these regulations in full, tradespeople can reduce risk, protect clients and demonstrate the professional competence that insurers, scheme providers and main contractors now expect as standard.
As a specialist building services training provider, at Logic4training, we see first-hand how up-to-date 18th Edition knowledge supports better design decisions, cleaner inspections and a healthier pipeline of work for electricians and multi‑discipline installers. Investing in accredited training and ongoing CPD not only helps you stay compliant, it also strengthens your reputation, opens up higher‑value projects and makes it easier to adapt as new amendments and technologies emerge.
Whether you are an electrician, contractor or related tradesperson, training with an experienced training centre like ourselves is one of the most effective ways to stay ahead in this fast‑moving industry.
FAQs
Who publishes the 18th Edition Wiring Regulations?
The BS 7671 18th Edition Wiring Regulations is jointly published by the Institution of Engineering and Technology (IET) and the British Standards Institution (BSI). The book is commonly known as the IET Wiring Regulations and is the main reference electricians use when designing, installing and certifying electrical work.
Do I legally have to follow the 18th Edition?
BS 7671 itself is not an Act of Parliament, but it is treated by the industry and the courts as the accepted standard of good practice. If there is an incident and you cannot show that your work complies with the current edition of the Wiring Regulations, it will be much harder to prove that you have met your legal duties under health and safety law.
Why are the 18th Edition Wiring Regulations important?
The regulations are widely recognised as the benchmark for electrical safety in the UK. Working to the 18th Edition helps reduce the risk of electric shock and fire, supports compliance with the Electricity at Work Regulations and related legislation, and is usually required by insurers, clients and Competent Person Schemes.
Is Amendment 4 the 19th Edition?
No. Amendment 4:2026 is an update to BS 7671:2018 (the 18th Edition), published as BS 7671:2018+A4:2026, not a brand‑new 19th Edition rulebook. It consolidates Amendments 1, 2 and 3 and adds new chapters and sections, so electricians still work to the 18th Edition, but with the latest A4 changes applied.
When does Amendment 4 become mandatory for electrical work?
Amendment 4:2026 is due to be published on 15 April 2026 and can be used voluntarily from that date alongside the previous version of BS 7671. After a six‑month transition period, Amendment 4 will become the mandatory version for all new electrical installation work in the UK, meaning designs and certification must reference BS 7671:2018+A4:2026.
Do I need to retake my 18th Edition course for Amendment 4?
If you already hold an 18th Edition qualification, you are not normally required to retake the full course when a new amendment is released, but you do need to update your knowledge. Scheme providers and clients are likely to expect evidence of CPD or an Amendment 4 update course demonstrating that you understand the new requirements for batteries, ICT earthing, PoE and medical locations.
What are the biggest practical changes in Amendment 4 for electricians?
The headline changes in Amendment 4 include a new chapter on stationary secondary batteries, new sections on functional earthing for ICT systems and Power over Ethernet, and a major rewrite of the rules for medical locations. There are also updates to inspection and testing, model forms and cable rating data, which affect day‑to‑day design, installation and certification work across domestic, commercial and industrial projects.
How will Amendment 4 affect domestic electricians?
For domestic electricians, Amendment 4 matters most where installations involve battery storage, EV charging, PV systems, smart home infrastructure or PoE devices. Understanding the new requirements helps you design and certify compliant installations, avoid issues at scheme audits and reassure homeowners that their systems meet the latest safety and performance standards.
How can Logic4training help me get ready for Amendment 4?
Logic4training delivers 18th Edition Wiring Regulations training and update pathways designed to bring electricians and multi‑discipline installers up to speed with the latest version of BS 7671. With centres in Northolt, Luton, Basildon and Sittingbourne, our courses and CPD support focus on the real‑world application of Amendment 4, helping you understand the new rules, pass the assessment and demonstrate current competence to schemes and employers across the South East.
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