BS 7671:2018+A4:2026 – What's New in Amendment 4? (Complete Guide)

amendment 4 just dropped and its not a minor PDF tweak like amendment 3 was

this ones a proper rewrite covering batteries, smart tech, and PoE because the IET finally caught up with what everyones actually installing

heres everything you need to know without reading 600 pages

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Quick Summary

the headline

amendment 4 (2026) is massive - not just a bolt-on like A3

addresses renewables, battery storage, smart tech, and medical locations properly

key dates

published: 15 april 2026

withdrawal date: current version (18th edition + A2 + A3) gets binned 15 october 2026

after that date A4 is mandatory

the book

say hello to the new orange book wiring regulations

its fully consolidated - everything from 2018 to now in one physical book

no more carrying brown book plus separate PDFs for amendments

major focus areas

stationary battery storage (new chapter 57), power over ethernet, functional earthing for ICT systems, medical locations overhaul

basically all the stuff we've been winging based on manufacturer pamphlets now has proper regs

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Timeline & Effective Dates

15 april 2026 - publication date

you can start designing and installing to this standard immediately

15 april to 15 october 2026 - transition period (6 months)

during this window you can use either old brown book combo or new orange book

15 october 2026 - the cut-off

after this A4 is mandatory for all new low-voltage electrical installations, additions, and periodic inspections

sparky tip

if youre pricing large commercial job now that wont start until late 2026 you must design it to amendment 4 standards today

dont get caught out by october cut-off thinking youve got ages

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What Makes Amendment 4 Different?

consolidation

finally got single book again

no more carrying brown book then checking separate PDF for amendment 3s unidirectional protective device rules

A4 rolls A1, A2, A3, and new A4 changes into one physical orange book

the why

IET and CENELEC playing catch-up

homes arent just consuming energy anymore - theyre mini power stations with solar plus battery

A4 standardizes the rules so were not just relying on vague manufacturer instructions and hoping for the best

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Key Changes in Amendment 4

1. stationary secondary batteries (NEW CHAPTER 57)

the reality

battery energy storage systems (BESS) everywhere now

weve been installing them in lofts and under stairs based on guesswork and whatever the battery manufacturer PDF said

whats covered

new chapter 57 lays down the law for domestic and commercial battery storage

fire & siting

strictly aligns with PAS 63100

expect strict rules on thermal management, ventilation, fire segregation

say goodbye to installing heavy lithium racks in high-risk areas like loft spaces or primary escape routes

if it blocks the fire exit it cant go there anymore - simple as that

isolation

clearer mandates on safe isolation procedures and managing backfeed risks from battery inverters during grid outages

no more guessing if its actually isolated when youre working on it

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2. power over ethernet (PoE) – SECTION 716 (NEW)

what is it

sending DC power and data down same cat5/cat6 cable

used to just be office phones - now its powering high-wattage LED smart lighting, access control, CCTV arrays

the problem A4 solves

heat

when you bundle 50 PoE cables together delivering up to 100W each they get dangerously hot

weve all seen the melted trunking

new rules

section 716 provides strict guidance on thermal management, cable ratings, routing for ELV DC distribution over balanced data cabling

forces you to treat data cables with same respect as twin and earth when it comes to grouping factors

cant just stuff 100 cat6 cables in 50mm trunking and hope anymore

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3. section 710 medical locations (MAJOR REVISION)

what changed

massive overhaul for healthcare settings - hospitals, dental practices, care homes

group 2 locations

power supply regulations tightened to absolutely guarantee no loss of power from single fault

redundancy is now mandatory not optional

documentation

BS 7671 medical locations now require brand new specific test schedule (annex B710) just for recording resistance of supplementary protective equipotential bonding conductors

more paperwork yeah but actually makes sense for liability

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4. functional earthing for ICT systems (NEW SECTION 545)

the issue

IT racks and server rooms have massive leakage currents

old regs didnt really cover this properly

the fix

section 545 draws hard line between protective earthing (stopping you getting shocked) and functional earthing (stopping data corruption and managing noise)

impact

if you work in commercial fit-outs, comms rooms, server environments the functional equipotential bonding rules have been completely rewritten

handles modern network infrastructure properly instead of pretending its 1995

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5. other notable changes

ferromagnetic enclosures (chapter 52)

regulation 521.5.1 revised to clear up confusion around grouping conductors entering ferrous metal enclosures like metal consumer units

prevents electromagnetic eddy currents that cause overheating

energy efficiency (chapter 81)

new framework for improving energy efficiency in LV installations

basically future-proofing for upcoming building regs

AFDDs

expanded guidance on where arc fault detection devices should or must be installed

still not mandatory everywhere but heading that direction

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Amendment 3 vs Amendment 4: Quick Comparison

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What This Means for Your Work

for new installations

start integrating chapter 57 battery rules into your solar/BESS quotes immediately

if youre pulling data cables for PoE lighting recalculate your cable grouping to account for heat build-up under new section 716

dont wait until october - learn it now

for EICRs and periodic testing

grandfather rights

installations done before april 2026 to older standards dont automatically become "unsafe"

they were compliant when installed

coding

youll need to update your coding logic

battery installed in loft escape route might now warrant C2 under new chapter 57/PAS 63100 alignment where it was C3 before

software side

new annex B710 medical bonding schedules and battery inspection checklists are getting pushed to TestFast on april 15th

if youre still handwriting certs youll be manually adding new observation templates and updated schedules yourself

we built it so the updates just appear - you open the app and the new A4 forms are already there

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for training and certification

do i need to retrain?

yes and no

dont need full 3-day 18th edition course again if you already hold it

but NICEIC and training providers (C&G/EAL) rolling out 1-day "amendment 4 CPD refresher" courses

EAS 2024 shift

scheme providers cracking down

if youre doing high-risk work like solar PV or EICRs the "qualified supervisor" umbrella is shrinking

you need to prove your own individual competence with updated regs

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How to Get Amendment 4

sources

pre-order from IET, BSI, or via trade bodies like NICEIC and NAPIT

format

available in digital (vitalsource) or physical orange book

sparky tip

scheme providers require you to have access to current edition to keep your accreditation

order it before october cut-off or youll fail your annual assessment

no point trying to blag it with old brown book when assessor shows up

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Updating Your Certificates and Schedules

the manual route

buy orange book, read chapter 57, rewrite all your cert templates, add new observation dropdown options, create annex B710 forms from scratch

takes about 2 days if youre quick

the TestFast route

we read the regs, built the templates, tested them against sample inspections

updates push to your account late april - new battery inspection schedules, medical location annex B710, updated observation library with chapter 57 codes

costs same monthly rate, saves you 2 days work

not saying you need it but if youre doing 5+ certs a week the time adds up

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Frequently Asked Questions

is amendment 4 mandatory?

for new designs signed off after 15 october 2026 - yes legally binding

for existing installations - no, you code them against current standard but dont force upgrades unless genuinely unsafe

can i still use amendment 2+3 after april?

yes, 6-month transition period allows you to use old books until 15 october 2026

after that youre out of time

do battery storage systems need special certification?

yes, alongside standard electrical certs chapter 57 pushes alignment with fire safety (PAS 63100) and proper DNO notification (G98/G99)

cant just slap a battery in and call it done anymore

will my EICR software be updated?

TestFast updates go live 15 april automatically - new observation codes, updated cert templates, chapter 57 battery inspection schedules

you dont download anything or click update - just open the app and its already done

if youre on paper certs or old desktop software youre manually rewriting templates which is grim

do i need the orange book if i have the brown book?

after october 2026 yeah you do

brown book will be officially withdrawn

scheme providers will check you have current edition during assessments

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Quick Summary

published: 15 april 2026

mandatory from: 15 october 2026

big changes: battery storage (chapter 57), PoE (section 716), medical locations (section 710), ICT functional earthing (section 545)

format: consolidated orange book - everything in one place finally

action required: order the book, book CPD refresher if doing specialist work, update your quotes and designs now not in september

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questions people ask

when does BS 7671 amendment 4 come out?

published 15 april 2026, becomes mandatory 15 october 2026 after 6-month transition period

whats new in amendment 4?

new chapter 57 for battery storage, section 716 for power over ethernet, major medical locations overhaul, functional earthing for ICT systems, plus energy efficiency framework

do i need to buy the orange book?

yes if youre doing any work after october 2026. brown book gets withdrawn. scheme providers check you have current regs

can i still use amendment 2 after amendment 4?

only until 15 october 2026. after that A4 is mandatory for all new work

what is chapter 57 BS 7671?

new chapter covering stationary battery energy storage systems - installation, fire safety, siting, isolation. aligns with PAS 63100

does amendment 4 affect EICRs?

yes - new observation codes, updated test schedules including annex B710 for medical, different coding logic for batteries in escape routes

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thats everything on amendment 4 without the waffle

order the book, learn chapter 57 if you do solar, and dont leave it until september