BS 7671 Amendment 4: what actually changes on site
- Evelia
- Aug 6
- 5 min read
The wiring regs changed in April. Most electricians know that much. What
fewer people have worked out is that the clock on the old version runs out
on 15 October 2026, and after that date the version sitting in the back of
the van is withdrawn.
start working to it the same day. The previous consolidated version, BS
7671:2018+A2:2022+A3:2024, is withdrawn six months later. That gives you
roughly ten weeks from now.
This is not a paperwork exercise. Amendment 4 is the biggest update to the
18th Edition since Amendment 2 in 2022, and the areas it touches are the
ones that have grown fastest in the last five years.
What changed, and where it lands
Battery storage got its own chapter. This is the headline change and it
matters most to anyone fitting domestic or commercial storage. Until now,
stationary secondary batteries were covered in pieces scattered across the
standard. Amendment 4 pulls them into a dedicated chapter covering design,
bidirectional energy flow, ventilation and fire risk.
If you have been fitting battery systems alongside solar for the past
three years, you have been working to guidance that was written before the
technology was common. That gap is now closed, and the requirements are
more specific than what most installers have been applying.
Power over Ethernet has its own section. Section 716 now gives specific
guidance on powering equipment through Ethernet cabling, including
requirements around continuous operating current per contact. If you fit
cameras, access control, wireless access points or lighting control, this
is your section.
PoE has quietly become electrical work while the paperwork treated it as
data. That is no longer the case.
Functional earthing for ICT equipment. A new section deals with functional
earthing and functional equipotential bonding for information and
communication technology. Anyone working in offices, data rooms or
commercial fit-out will meet this.
Medical locations were substantially revised. Section 710 has had a major
overhaul, and it now includes a schedule of test results for recording the
resistance of supplementary protective equipotential bonding conductors.
If you do not work in healthcare settings, you can skip this. If you do,
it is the most significant change on the list for you.
Amendment 3 is now inside the main document. A3:2024 was a standalone
publication with a brown cover, referenced alongside the main standard.
It is now incorporated into the consolidated document, which is why
Amendment 4 arrives with an orange cover rather than as another bolt-on.
Energy efficiency also gets its own chapter, which points the reader to
the relevant Building Regulations rather than duplicating them.
What this means for your business, not just your knowledge
The technical changes are the part everyone talks about. The commercial
changes are the part that costs money if you miss them.
Three things follow from an amendment cycle, and they arrive in this
order.
Your certificates change. Test results schedules and certification
formats follow the standard. If you use a certification app or a printed
pad, check what version it produces before you issue the next one. A
certificate referencing a withdrawn standard is an awkward thing to have
to reissue six months later.
Your product selection needs a second look. Protective devices, inverters,
cabling and supporting equipment may need closer scrutiny under the new
requirements, particularly around battery storage. That is a conversation
worth having with your wholesaler before you price the next storage job,
not after you have won it.
Your quotes are now pricing against a moving target. Any job you are
quoting today that will be commissioned after 15 October needs to be
priced against Amendment 4, not against what you did last spring. If the
new requirements add labour or change the spec, that difference belongs in
the quote rather than in your margin.
What to do before October
Book the training. Most awarding bodies have already moved. If you hold
the 18th Edition qualification you will not need to retake the whole
thing, but you do need to update your knowledge, and the courses fill up
as the deadline approaches. Leaving it until September is a common and
expensive mistake.
Buy the book. BS 7671:2018+A4:2026 is the consolidated version, orange
cover. If your reference copy is the brown one, it is about to be out of
date.
Check what your certification tools produce. This is the one that catches
people out, because it is not obvious until a certificate has already gone
to a client.
Look at your standard job templates. If you have saved quote templates or
standard specifications for storage or PoE work, they were built against
the old requirements.
None of this is dramatic. It is the same cycle that has run every few
years since the 18th Edition landed in 2018. The difference this time is
that the changes cluster around the work that has grown fastest, which
means more electricians are affected than in a typical amendment.
A note on where this sits in the business
Regulation changes are one of the few things in this trade that arrive
with a fixed date attached. Everything else, from a quote going out late
to a certificate going missing, happens quietly and gets noticed later.
If keeping certificates, test results and job records in one place is
currently a mix of an app, a folder and somebody's phone, an amendment
cycle is a reasonable moment to fix it. Not because the regs require it,
but because you are going to be touching all of that paperwork anyway
over the next ten weeks.
Frequently asked questions
When does Amendment 4 come into force?
It was published on 15 April 2026 and can be used immediately. The
previous version, BS 7671:2018+A2:2022+A3:2024, is withdrawn on 15
October 2026.
Do I need to retake the 18th Edition qualification?
No. If you already hold the 18th Edition, you need to update your
knowledge rather than requalify. Awarding bodies have released updated
courses covering the changes.
What is the biggest change for domestic work?
The new chapter on stationary secondary batteries. If you fit battery
storage, particularly alongside solar, this is the section to read first.
Does Amendment 4 affect certificates?
Yes. Certification formats and test result schedules follow the standard,
and Section 710 introduces a new schedule for supplementary bonding
resistance. Check what version your certification tool produces.
What happens if I work to the old version after October?
The previous version is withdrawn, so new designs and installations should
comply with the current standard. Working to a withdrawn standard is
difficult to defend if anything is ever questioned.
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