18th Edition Amendment 4: What UK Electricians Need to Know (October 2026)

From 15 October 2026, BS 7671:2018+A4:2026 is the only current version of the IET Wiring Regulations. The previous edition — BS 7671:2018 with Amendments 1, 2, and 3 — has been formally withdrawn. Any electrical design, installation, inspection, or testing work carried out in the UK must now comply with Amendment 4.

This is not a wholesale rewrite of the standard. But there are meaningful technical changes — particularly for EV charging, solar PV, and battery storage — that every practising electrician needs to understand.

What Is BS 7671 and Why Does It Matter?

BS 7671 is the IET Wiring Regulations — the standard against which all UK electrical installation work is designed, installed, and inspected. Published jointly by the IET and BSI, it is the universally accepted method of demonstrating compliance with Part P of the Building Regulations in England and Wales, and the equivalent regulations in Scotland and Northern Ireland.

Amendment 4 was published in April 2026. Firms could use it from that date. From 15 October 2026, it is mandatory — the previous version is withdrawn and no longer provides a valid basis for compliant work.

What Changed in Amendment 4?

The main technical changes fall into four areas:

1. Electric Vehicle (EV) Charging (Section 722)

This is the most significant area of change for domestic electricians. Key updates:

• Smart charging requirements. Domestic EV charge points installed from October 2026 must be capable of smart (demand-managed) charging, aligning BS 7671 with the Electric Vehicles (Smart Charge Points) Regulations 2021.
• RCD protection clarified. Requirements for residual current device protection on EV charging circuits have been updated, including for Mode 3 (AC) and Mode 4 (DC rapid) charging.
• PME earthing guidance. Protective multiple earthing (PME) on TN-C-S supplies and EV charging has been a known safety risk for years. Amendment 4 provides clearer, more prescriptive guidance on when a separate earth electrode is required — which is most domestic situations. This is a safety-critical update.

2. Solar PV and Battery Storage (Section 712)

• Updated isolation and fuse requirements for PV string circuits
• Revised arc fault detection requirements for PV arrays
• New requirements for battery energy storage systems (BESS) connected alongside PV — reflecting the rapid growth in domestic battery installations

3. Arc Fault Detection Devices (AFDDs)

Expanded recommendations (and in some cases requirements) for AFDDs in high-risk locations. The standard now more explicitly addresses where AFDDs should be considered — relevant for new domestic installations and consumer unit replacements.

4. Technical Clarifications Throughout

Updates to cable current-carrying capacities, fault current calculations, and installation methods in the core installation chapters. These are technical refinements rather than new requirements, but worth reviewing if you use the tables directly.

Do You Need to Retrain?

If you hold an 18th Edition (City & Guilds 2382-18) qualification: You do not need to sit a new exam. The 2382-18 qualification covers BS 7671:2018 as amended — the amendment number is not part of the qualification. However, as a competent person, you are expected to work to the current version of the standard. Most approved schemes (NICEIC, NAPIT, ELECSA) check your awareness of current standards as part of ongoing registration.

What you should do: At minimum, read the Amendment 4 summary document (available from the IET or your scheme's member portal). If you carry out EV charging or solar PV work, complete a CPD update course on the specific changes — half-day and one-day courses are available from most training providers.

If you hold only a 17th Edition qualification: You should already have updated. The 17th Edition has been superseded for years — work to it is non-compliant.

For EV charging and solar PV specifically: The Amendment 4 changes are most significant here. If you carry out this work, familiarise yourself with the updated Section 722 and 712 requirements before completing new installations.

Amendment 4 and the EAS Changes: How They Relate

October 2026 brought two separate but related changes:

• BS 7671 Amendment 4 — the technical standard for how work is designed and installed. Mandatory from 15 October.
• EAS (Electrotechnical Assessment Specification) changes — the competence framework defining what qualifications you need to do that work within an approved scheme. In force from 1 October.

The EAS changes introduced new, separate competence categories for EV charging, heat pump electrical connections, and solar PV. There are no grandfather rights for these categories. Even if you've been doing EV charging work for years, you now need to evidence the specific EAS competence qualification.

See our full article on EAS changes October 2026 for the qualification requirements.

How Amendment 4 Affects Your Day Rate

Electricians who are current — working to Amendment 4 and holding the relevant EAS competences for low-carbon work — are in a materially stronger market position than those who are not.

EV charger installation is growing at pace: every new-build home requires EV charging provision under Part S of the Building Regulations. The heat pump market is growing at 35% year-on-year, and every heat pump installation requires a qualified electrician for the wiring. The skills shortage in these specific areas is acute.

Use the day rate calculator to make sure your rate reflects your current qualification level and the market premium for low-carbon technology work.

Practical Checklist for Electricians

• Obtain or access BS 7671:2018+A4:2026 — IET bookshop or your scheme's member portal
• Read the IET Amendment 4 summary document (free download from theiet.org)
• If you do EV charging work: read the updated Section 722, particularly PME earthing guidance
• If you do solar PV or battery storage: read the updated Section 712
• Complete a CPD update course if you carry out EV charging, PV, or BESS work
• Check your scheme registration is current — NICEIC, NAPIT, ELECSA, ECA all have specific guidance
• Update your installation certificate and EICR templates to reference BS 7671:2018+A4:2026
• Review your inspection and testing qualifications separately — 18th Edition ≠ 2391 competence

Frequently Asked Questions

Is BS 7671 Amendment 4 now mandatory? Yes. From 15 October 2026, Amendment 4 is the current edition. The previous version — BS 7671:2018 with Amendments 1–3 — has been formally withdrawn. All UK electrical installation work must now comply with BS 7671:2018+A4:2026.

Does my 18th Edition qualification become invalid? No. The City & Guilds 2382-18 qualification covers BS 7671:2018 as amended — it does not expire when an amendment is issued. However, you are expected to work to the current version of the standard, which now includes Amendment 4.

What specifically changed in Amendment 4? The main technical changes are in EV charging (Section 722 — especially PME earthing and smart charging), solar PV and battery storage systems (Section 712), and arc fault detection device (AFDD) recommendations. There are also technical clarifications throughout the standard.

Do I need to redo my 18th Edition exam? No. You do not need to resit the 2382-18 exam. However, if you carry out EV charging or solar PV work, complete a CPD update course on the Amendment 4 changes and check your EAS competence qualifications are in order.

What is the PME earthing issue with EV charging? Most domestic properties in the UK have a TN-C-S (PME) supply. Connecting an EV charger directly to the PME earth creates a risk of touch voltage if the neutral conductor fails. Amendment 4 provides clearer guidance: in most domestic PME situations, a separate earth electrode is required for the EV charging circuit. This was best practice before, but is now more explicitly required.

Where can I get the updated standard? The IET bookshop at theiet.org, or through your scheme's member portal (NICEIC, NAPIT, ELECSA, ECA members typically get access). The IET also publishes a free Amendment 4 summary document.

Does Amendment 4 affect EICRs on existing installations? Existing installations are assessed against the standard in force when they were installed — you are not required to upgrade everything to Amendment 4. However, your EICR report and any recommendations should reference current standards, and any new work carried out as part of remediation must comply with Amendment 4.

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Written by Russell Brooks, Founder of Sleepless Tradesman. Published 31 October 2026.