BS 7671 Explained: What the UK Wiring Standard Means for Plug In Solar and Home Batteries

BS 7671 is the UK's national standard for electrical installations, published jointly by the IET and BSI and widely known as the IET Wiring Regulations. It is not an Act of Parliament, yet several laws point to it, so almost every fixed wiring job in a home is designed, tested and certified against it.

That makes it relevant to plug in solar as well as to hardwired batteries. This guide explains how the standard works, what the current edition changed, why it kept plug in solar off the market until 2026, and what it means for a battery installation.

What is BS 7671 and who publishes it?

BS 7671 sets out how low-voltage electrical installations should be designed, built, inspected and tested so they are safe to use. The IET says it co-publishes the standard with BSI and runs JPEL/64, the technical committee that keeps it up to date.

The standard is written for fixed installations: cables, consumer units, protective devices and circuits that stay put inside a building. That focus explains why plug in solar needed new rules, because a panel connected through a socket does not fit neatly into a framework built around permanent wiring.

• Design, such as how circuits are arranged and protective devices chosen
• Selection and erection of equipment
• Inspection and testing before an installation is put into service
• Certification recording that the work was checked

Is BS 7671 a legal requirement in the UK?

On its own, BS 7671 is a non-statutory standard. Its weight comes from the laws that reference it, which is why a search for electrical regulations UK returns a mix of Acts, regulations and British Standards.

How do law, standard and guidance fit together?

It helps to picture the electrical wiring regulations UK installers work to as three layers.

1. Law: the DESNZ consultation document explains that the Electricity Safety, Quality and Continuity Regulations 2002 (ESQCR) expect installations to meet British Standard requirements, chiefly BS 7671. Part P of the Building Regulations covers electrical safety in homes in England and Wales, and guidance generally cites the Electricity at Work Regulations 1989 as a further route.
2. Standard: BS 7671 supplies the technical detail. Electrical Safety First describes it as the national standard used to confirm that work satisfies Part P.
3. Guidance: Approved Document P, published by government in 2013, explains when work must be notified and how it should be designed, installed and tested. The IET also publishes a Code of Practice for Electrical Energy Storage Systems.

Electrical Safety First notes that Scotland relies on its Building Standards system instead, while Northern Ireland currently has no statutory equivalent of Part P.

What changed with BS 7671 Amendment 4?

The IET confirms that BS 7671:2018+A4:2026 is now the current edition. The transition period for Amendment 2 closed on 15 October 2026, so A2 can no longer be used for new work, specifications or certification, and the IET offers free Model Forms for the new edition.

According to listings on the IET shop, BS 7671 Amendment 4 was published on 15 April 2026 and is nicknamed the orange book. Check the current edition for exact wording, but the headline changes are described as:

According to the IET's listing for the amendment, the headline additions include a dedicated chapter on stationary secondary batteries used for storage, new rules for functional earthing and bonding of ICT equipment, and a fresh section on Power over Ethernet. For homeowners, the battery chapter is the part that matters most.

For solar households, the battery chapter matters most, giving electricians dedicated requirements for storage. Amendment 4 is also described as cross-referencing PAS 63100, the BSI specification on battery fire protection and siting in dwellings. None of this changes the separate route for plug in solar kits without storage.

What did Amendment 3 add for solar and batteries?

IET material indicates that Amendment 3, published on 31 July 2024, introduced the terms bidirectional protective device and unidirectional protective device, plus Regulation 530.3.201, which asks designers to choose devices with the direction of current flow in mind.

That matters wherever power can travel back through a circuit, as with solar inverters and batteries feeding energy towards the consumer unit.

Why did BS 7671 and BS 1363 block plug in solar?

Until late August 2026, plug in solar could not lawfully be sold, supplied or used in Great Britain. The DESNZ consultation document gave two reasons, and both lead back to British Standards.

2. ESQCR requires installations to follow British Standard requirements, mainly BS 7671, which was designed around fixed wiring rather than generators connected through sockets.
3. The Plugs and Sockets etc. (Safety) Regulations 1994 (PSSR) require plugs to meet BS 1363, which does not allow plugs and sockets to connect electricity-generating equipment.

The government's fix was a package. It amends PSSR so compliant plug in solar can use a BS 1363 plug, introduces an Interim Product Specification (IPS) with minimum safety requirements, changes G98 so IPS-compliant plug in solar devices can join low-voltage networks, and amends ESQCR.

Longer-term standards, including updates to BS 7671 and BS 1363, are still being developed. DESNZ announced that plug in solar became legal to buy and use across Great Britain from 27 August 2026, for kits up to 800W. The 2026 amending regulations are reported as S.I. 2026/848; check that reference on legislation.gov.uk.

What does the IPS leave out?

The IPS applies to plug in solar without batteries. DESNZ states that plug-in batteries and small wind fall outside it, and Northern Ireland follows separate rules under ESQCR (NI) 2012 and G98/NI. A home battery therefore still takes the conventional route of fixed wiring, building regulations compliance and grid notification.

How does BS 7671 apply to a hardwired battery like the Solarbank 4 E5000 Pro?

This is why the Solarbank 4 E5000 Pro is treated as fixed wiring today rather than a socket appliance. Its hardware anticipates a future plug-in option, yet Anker's UK product page, checked at the time of writing, rules that route out for now: a Part P-registered electrician connects it on a dedicated circuit back to the consumer unit, together with the Anker SOLIX Smart Meter Gen 2, and tests the work to BS 7671.

A new dedicated circuit is exactly the kind of fixed installation BS 7671 covers, and guidance generally lists a new circuit as notifiable work in England. Unlike plug in solar, this is not a homeowner job.

Per the official Anker SOLIX datasheet, the unit stores 5,024Wh in LiFePO4 cells, delivers up to 2,500W of on-grid AC output and uses an isolated inverter topology with Protective Class I and IP66. The full specification is listed on the Solarbank 4 E5000 Pro product page.

• Designing the circuit and choosing protective devices that handle two-way power flow
• Modifying the consumer unit where needed, as Anker notes may be necessary
• Agreeing a location that reflects PAS 63100 fire safety guidance
• Inspecting and testing the circuit before use
• Submitting G98 documentation to the DNO within 28 days of commissioning, as Anker describes for this G98-listed unit

Which certificates should you receive after the install?

Electrical Safety First says you should receive an Electrical Installation Certificate or Minor Works Certificate confirming the work meets BS 7671, plus a Building Regulations Compliance Certificate. Guidance generally says the occupier should get the compliance certificate within 30 days of completion.

Keep both with the G98 notification. Anker ships the unit with an 800W default AC output, and owners email installation proof to its support team to receive an app unlock password for 2,500W.

How do plug in solar kits and battery systems compare?

Plug in solar and hardwired batteries reach the wiring rules by different paths: a panel-only plug in solar kit relies on the IPS and a compliant BS 1363 plug, while a battery depends on fixed wiring designed to BS 7671. The table compares headline figures only.

Figures were taken from each brand's UK store and the Energy Saving Trust on 30 October 2026; prices move often, so check them again before buying.

Read each manufacturer's UK instructions rather than assuming how a battery connects. For plug in solar, the Energy Saving Trust notes compliant kits are limited to roughly 800W and daisy chaining is not currently allowed.

What should you ask an electrician about BS 7671 before a battery install?

A few targeted questions show whether an installer works to the current edition and understands storage, which follows different rules from plug in solar.

3. Will the certificate reference BS 7671:2018+A4:2026?
4. Are you registered with a competent person scheme? Gov.uk lists schemes including NAPIT and Certsure for domestic electrical work.
5. How will you choose protective devices for current flowing back from the battery?
6. Where should the unit go, and how does that fit with PAS 63100?
7. Will you submit the G98 notification and send me a copy?
8. Which certificates will I receive?

Anker suggests searching the MCS, NAPIT or NICEIC tools for battery storage installers and cross-checking at least two. Share the Solarbank 4 E5000 Pro specifications so quotes are based on the right equipment. If you already own plug in solar and want storage, treat the battery as a new installation, not an extension of the plug in solar rules.

This guide explains the framework rather than giving legal advice, so confirm details for your property with your electrician, DNO and energy supplier.

Conclusion

BS 7671 sits at the centre of UK home electrics: law sets the duty, the standard supplies the method and guidance explains the process. Amendment 4 is now the edition to work to, with a dedicated battery chapter.

The legal route for plug in solar was built alongside the wiring standard rather than through it, and it stops short of batteries. For a hardwired unit such as the Solarbank 4 E5000 Pro, a registered electrician, an EIC and a G98 notification remain the expected path.

If you are planning a battery installed to the current wiring standard, compare the specification on the Anker SOLIX Solarbank 4 E5000 Pro UK page and share it with your electrician.

Frequently Asked Questions

Can electricians still certify new work to Amendment 2?

No. The IET states that the transition period for BS 7671:2018+A2:2022 ended on 15 October 2026, so Amendment 2 is now obsolete for new work, specifications and certification. Certificates for jobs carried out today should reference BS 7671:2018+A4:2026, and the IET provides free Model Forms for that edition.

Is BS 7671 the same thing as the IET Wiring Regulations?

Yes, both names describe the same document. BS 7671 is the formal British Standard title, while IET Wiring Regulations reflects that the Institution of Engineering and Technology co-publishes it with BSI and runs the JPEL/64 committee that maintains it. Electricians often shorten either name to the regs in everyday conversation.

Does BS 7671 apply in Scotland and Northern Ireland?

The IET describes BS 7671 as the national standard for electrical installations across the UK. What differs is the building control route: Electrical Safety First explains that Scotland uses building warrants and approved certifiers, while Northern Ireland currently has no statutory equivalent to Part P. Check local requirements with your installer before work begins.

Does a Part P qualification let an electrician self-certify work?

Not on its own. Guidance generally describes a Part P qualification as a Level 3 award such as City & Guilds 2393-10. Self-certifying notifiable work also requires registration with a government-approved competent person scheme, which assesses the electrician's competence, insurance and test equipment before they can issue compliance certificates to customers.

How does PAS 63100 relate to BS 7671?

PAS 63100:2024 is a BSI specification on fire protection for battery storage in homes, and Amendment 4 is described as cross-referencing it. It generally advises against placing batteries in rooms where people sleep, on escape routes or in lofts and roof voids. Check the current edition with your installer before choosing a location.

Does meeting BS 7671 make a battery or plug in solar kit eligible for SEG payments?

Not by itself. BS 7671 compliance shows the wiring is safe, but SEG depends on supplier terms. The Energy Saving Trust says suppliers usually want MCS or equivalent certified technology and installation plus an export-recording smart meter, so plug in solar owners normally cannot use SEG, and grid-charged battery exports need not be paid.