Amendment 4 is already live. October 15th is when the previous version gets withdrawn and your certification paperwork needs to reflect the new standard. Here is what actually changes on your jobs.

What Are the Key Dates and What Do They Mean?

What Actually Changes on Your Jobs?

Amendment 4 is described by the IET as the most significant update since Amendment 2. Here is the plain-English version of the parts that affect day-to-day installation work for most UK electricians:

Chapter 57 — Stationary Secondary Batteries (NEW)

This is the biggest addition. Before Amendment 4, there was no dedicated chapter in BS 7671 for battery storage systems — solar batteries, home energy storage units like Givenergy or Tesla Powerwall, and commercial ESS installations. You were working to manufacturer guidance and best practice. Now there are specific requirements covering: location selection and ventilation, isolation requirements for bidirectional energy flow, protection against overcharge and overdischarge, labelling and documentation, and fire risk mitigation. If you install battery storage, this chapter is essential reading before your next job.

Section 716 — Power over Ethernet (NEW)

PoE — powering devices like IP cameras, VoIP phones, smart thermostats and access control panels through Ethernet cabling — is now formally within BS 7671's scope. Section 716 sets requirements for the PSE (Power Sourcing Equipment), cable ratings, separation from mains wiring, and earthing. For electricians working on commercial fit-outs, smart homes, or hotel installs where PoE-powered devices are specified alongside electrical work, this section now applies to you.

Section 443 — AFDD Guidance (EXPANDED)

Arc Fault Detection Devices were already in BS 7671 from Amendment 2. Amendment 4 expands the guidance significantly on where AFDDs should be installed, particularly in higher-risk premises — rented properties, properties with older wiring, and premises with vulnerable occupants. For electricians doing EICR work in rental properties, the expanded AFDD guidance will change how you write up recommendations. A property without AFDDs in the affected circuits is not automatically a C2 failure, but you need to understand the updated guidance to write accurate observation codes.

ICT Earthing and Functional Equipotential Bonding (NEW)

IT systems, server rooms, smart building infrastructure, and commercial AV installations have specific earthing requirements that were not clearly addressed before. The new sections on functional earthing for ICT equipment and functional equipotential bonding are particularly relevant for commercial electricians working alongside data/IT contractors.

Section 710 — Medical Locations (MAJOR REVISION)

This is mainly relevant to electricians working in healthcare. The revision is substantial and includes a new schedule of test results format for supplementary protective equipotential bonding. If you work in hospitals, dental practices, care homes, or any medical environment, Section 710 needs careful review before any new work.

Does Amendment 4 Affect the Accessories You're Already Installing?

For standard switches, sockets and wiring accessories — the bread and butter of domestic and light commercial work — Amendment 4 does not change the accessories themselves. BG Evolve and BG General sockets and switches manufactured to BS EN 60884 and BS EN 60669 remain fully compliant with BS 7671:2018+A4:2026. The same back box depths, the same circuit design rules for ring finals and radials, the same 13A socket requirements.

Where Amendment 4 introduces new product requirements is in battery storage circuits (new isolation and protection devices) and AFDD installations (the decision on where to fit them has now been more clearly defined). For most domestic electricians in the UK — replacing sockets in a Victorian terrace in Bristol, fitting a kitchen ring in a new build in Newcastle, or upgrading a consumer unit in an HMO in Leeds — the immediate impact of Amendment 4 is mainly about your certification paperwork and staying current with the guidance on AFDDs and battery storage when these come up.

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