BSI 2026 Plug-In Solar Tracker: BS 7671 A4, BS 1363, and the BSI Product Standard

At a glance: standards status

1. BS 1363-1:2023, UK 13A plugs and sockets

BS 1363 is the standard that defines the familiar UK 3-pin 13A plug and socket. The current edition is BS 1363-1:2023, and it governs the design, safety and testing of plugs, sockets and adaptors used in the UK.

The important point for plug-in solar is what BS 1363 does not do. UK 13A sockets are designed and approved as power outlets, the direction of energy flow is from the socket into the appliance. The standard does not currently cover backfeeding, the practice of pushing externally generated power into the socket from the plug end. Until BS 1363 is amended to cover that case, using a 13A wall socket as an inlet for solar generation sits outside the standard.

2. BS 7671:2018+A4:2026, the IET Wiring Regulations

BS 7671:2018+A4:2026 (the 18th Edition Amendment 4) was published on 15 April 2026 by the IET. It governs electrical installations in the UK, the wiring inside your walls, the protective devices in your consumer unit, and the rules an electrician follows when adding circuits.

Amendment 4 updates a range of rules across the wiring regulations. It does not authorise plugging small power-generating equipment into a 13A socket outlet, and it is not the same document as the BSI plug-in solar product standard. Where Amendment 4 touches on solar PV and energy storage, the rules are about installation practice (earthing, isolation, labelling, RCD protection, AFDDs), not about creating a new "plug it in like an appliance" route.

If you read a headline that says "BS 7671 Amendment 4 makes plug-in solar legal", treat it as inaccurate. The amendment is real and consequential, but its effect on plug-in solar is bounded by what BS 1363 still does not allow.

3. The BSI plug-in solar product standard, expected July 2026

BSI has indicated July 2026 for publication of a new product standard covering plug-in solar equipment. The document is a product specification: it sets out what a compliant plug-in solar product must do at the level of the kit itself, things like inverter behaviour, anti-islanding, connector type, labelling, safety testing.

What it changes:

• Manufacturers selling into the UK will have a clear specification to test against.
• Retailers will be able to verify a kit meets a UK-recognised product standard, rather than relying on European VDE marks.
• Electricians and DNOs will have a reference point when assessing equipment during a hardwired install.

What it does not change:

• BS 1363 still defines the 13A socket as a power outlet, not an inlet.
• BS 7671 still governs how electrical installations must be wired.
• For DIY plug-in via a 13A socket to become compliant in the UK, both BS 1363 and BS 7671 would also need to be amended in concert. A product standard alone cannot do that.

4. So what is compliant in the UK in 2026?

The compliant route for installing plug-in solar in the UK in April 2026 is straightforward, even if it is less convenient than "plug it into the wall":

1. Buy a kit with a microinverter that is G98-listed and meets either VDE-AR-N 4105 or the forthcoming BSI plug-in solar standard.
2. Engage a CPS-certified electrician (Competent Person Scheme: NICEIC, NAPIT, ELECSA, Stroma, etc.) to install a hardwired connection from the microinverter to a dedicated circuit on your consumer unit.
3. The electrician completes a Minor Works Certificate or EIC under BS 7671:2018+A4:2026.
4. The installer or you submit a G98 notification to your local DNO before energising. G98 covers single-phase installations up to 16A per phase, which comfortably includes typical 600W or 800W plug-in kits.

That route is compliant today, was compliant before 15 April 2026, and will remain compliant after July 2026 whether or not the BSI standard publishes on time.

5. Timeline of dated milestones

• 2023 BS 1363-1:2023 published

  Latest edition of the UK 13A plug, socket and adaptor standard. Does not cover backfeeding via a 13A socket.

• May 2024 Germany passes Solarpaket I

  Germany lifts plug-in solar feed-in limit to 800W and authorises Schuko-plug connection. Often confused in UK press with the UK position. The UK has not adopted the same rules.

• 2025 BSI announces work on plug-in solar product standard

  BSI begins the work programme for a UK product specification covering plug-in solar equipment.

• 15 April 2026 BS 7671:2018+A4:2026 published

  The IET publishes Amendment 4 to the 18th Edition Wiring Regulations. Updates wiring installation rules. Does not authorise plug-in via a 13A socket.

• July 2026 (expected) BSI plug-in solar product standard publishes

  Product specification for plug-in solar kits sold in the UK. This page will be updated with the document number and exact publication date when BSI confirms.

• Not announced Amendments to BS 1363 covering backfeeding

  No amendment to BS 1363 has been announced that would authorise using a 13A wall socket as an inlet for externally generated power. Until such an amendment is published, DIY plug-in via a 13A socket remains outside the standard.

6. What I will and will not say about timing

I have one rule on this site: I will not say plug-in solar via a 13A socket is "almost legal", "imminent", or "DIY-legal in July 2026". The legal picture depends on at least three documents (BS 1363, BS 7671, and the BSI product standard) moving in concert, and as of today only one of them has moved this year.

If you are writing a piece on plug-in solar in 2026 and you want a phrasing that will not be wrong in six months, you can borrow any of these:

• "The BSI plug-in solar product standard is expected to publish in July 2026."
• "Even after the BSI standard publishes, the compliant UK install route remains a CPS-certified electrician with a hardwired connection."
• "BS 1363 currently does not cover using a 13A wall socket as an inlet for externally generated power."
• "DIY plug-in via a 13A socket is not currently compliant in the UK and is not made compliant by the BSI product standard alone."

7. Primary sources

• BSI: BS 1363-1:2023, specification for 13A plugs, socket-outlets and adaptors
• IET: BS 7671 Wiring Regulations (18th Edition) Amendment 4:2026
• BSI: standards programme and announcements
• Energy Networks Association: ENA EREC G98 (small generator connection)
• UK Government press releases on plug-in solar

If a source above moves or is updated, this page will be updated within 7 days. Corrections and challenges are welcome at [email protected].

8. Frequently asked questions

• Will the BSI 2026 plug-in solar standard make it legal to plug a solar kit into a UK 13A wall socket?
  No, not on its own. The BSI plug-in solar standard expected in July 2026 is a product specification. For DIY plug-in via a 13A socket to become compliant in the UK, BS 1363-1:2023 (which governs 13A plugs and sockets) and BS 7671:2018+A4:2026 (the IET Wiring Regulations) would also need to be amended. Until that happens, the compliant route is a CPS-certified electrician with a hardwired connection to your consumer unit.
• What did BS 7671:2018+A4:2026 actually change?
  BS 7671:2018+A4:2026 (the 18th Edition Amendment 4) was published on 15 April 2026 by the IET. It updates wiring installation rules. It does not authorise plugging small generating equipment into a 13A socket outlet, and it is not the same document as the BSI plug-in solar product standard.
• Is plug-in solar legal in the UK in 2026?
  A plug-in solar product can be sold in the UK, and a hardwired installation by a CPS-certified electrician with G98 notification to the local DNO is compliant. Connecting via a UK 13A wall socket is not currently covered by BS 1363 or BS 7671, and the BSI product standard does not by itself change that.
• When does the BSI plug-in solar standard publish?
  BSI has indicated July 2026 for publication of the plug-in solar product standard. This page is updated when BSI confirms the document number and publication date.
• What is the compliant install route for plug-in solar in the UK today?
  A CPS-certified (Competent Person Scheme) electrician completes a hardwired connection from the microinverter to a dedicated circuit on your consumer unit, then submits G98 notification to your DNO before energising. This route is compliant with BS 7671 and existing DNO rules.
• Is the UK following Germany's Solarpaket I model?
  Not directly. Germany's Solarpaket I (May 2024) raised its plug-in feed-in limit to 800W and authorised the Schuko plug as an inlet, but Germany's wiring rules and socket standard work differently to the UK's. The UK is taking the product-standard route first via BSI. There is no announced UK amendment that mirrors the Schuko-plug authorisation.
• Where can I track changes to this page?
  The "Last reviewed" date in the author box and the "Updated" badge in the header reflect the most recent fact check. Substantive corrections are logged on the site changelog. If you are a journalist or electrician and want to be notified when this page changes, email me at [email protected].

Related reading: Complete UK Guide to Plug-In Solar · G98 / DNO Notification Guide · Renter Guide · FAQ