There is no BSI standard for plug-in solar: here is what actually governs it
No British Standard and no PAS covers plug-in solar. What gives the rules legal force is a departmental interim specification derived from a German pre-standard, and an earlier draft of it has already been withdrawn.
There is no British Standard for plug-in solar. There is no PAS for it either. If a product page, a press release or a comparison article tells you a kit is “BSI-certified” or “PAS-compliant” for plug-in solar, the claim is false, because the document it would have to comply with does not exist.
This is the most widely repeated error in UK coverage of the 27 August 2026 changes, and it matters commercially: it is exactly the sort of phrase that makes a shopper stop checking. What actually governs these devices is newer and much less settled than a British Standard, and it is worth understanding what you are relying on.
What actually carries legal weight
The operative document is the Interim Product Specification, published on 16 July 2026 by the Department for Energy Security and Net Zero. On its own, a departmental specification is guidance. It acquires legal force because SI 2026/848 names it: the amendment to regulation 8 of the Plugs and Sockets etc. (Safety) Regulations 1994 permits a notified body to approve a plug for a plug-in microgenerator that deviates from BS 1363 only as regards the provisions restricting generation use, and only where the device otherwise fully complies with BS 1363 and complies with the Interim Product Specification.
So the chain runs: statutory instrument, then interim specification, then the individual British and European standards the specification cites. There is no plug-in-solar British Standard anywhere in that chain.
The specification is adapted from a German pre-standard
The Interim Product Specification is based on DIN VDE V 0126-95:2025-12. The “V” matters: in the German system it marks a Vornorm, a pre-standard. That is a provisional document issued where a subject is moving too fast, or is too unsettled, for a full standard to be justified yet. Germany has had a mass market in balcony solar for several years, so borrowing its technical work was a sensible way to move quickly. But the UK has adopted a provisional foreign document, translated into a domestic context, and given it legal effect by reference. The result is a pragmatic solution that stops well short of a mature standards regime.
The specification does lean on real published standards for its component parts. Plugs to BS 1363-1 with a BS 1362 fuse of not more than 5 A, sockets to BS 1363-2, protection class per BS EN 61140, residual DC current limits per BS EN 62109-1 clause 7.3.8, and installation to BS 7671:2018+A4:2026, cited normatively. Those are all genuine. What does not exist is a single standard that says “this is what a plug-in solar device is and how you certify one”.
An earlier draft has already been withdrawn
A draft specification published on 16 June 2026 is now marked [Withdrawn]. The version that counts is the one published on 16 July 2026 alongside the consultation response.
That is not a scandal. Documents get revised, and a withdrawn draft that is clearly marked is the system working. But it does tell you something about how young this framework is, and it creates a practical hazard. Articles, retailer FAQs and manufacturer datasheets written in late June may cite the withdrawn draft in good faith. If a source you are reading quotes specification detail, check which version it is working from before you rely on it.
Two claims that should stop a purchase. “Certified to the British Standard for plug-in solar”: there is no such standard. “PAS-approved plug-in solar”: there is no such PAS. Either phrase means the seller is careless with technical claims or hoping you will not check, and neither is a good sign on a product you are going to plug into your ring main.
No long-term standard has a name or a date
The government’s commitment is that work “will begin” on a longer-term successor to the interim specification. That is the whole of it. As at the date of this article there is no designated document, no named publisher, no drafting timetable and no target date. Nobody can tell you whether the eventual successor will be a British Standard, a PAS, an updated departmental specification or something adopted from European work.
Two consequences follow for a buyer. First, the compliance position of a device bought in 2026 could change if a future document sets different requirements, and nothing in the current framework promises grandfathering. Second, treat any confident prediction about a forthcoming standard as speculation, including predictions of the reassuring kind.
What a buyer can verify instead
Since there is no certification mark to look for, the check that works is the register. Manufacturers must register a device on the ENA Type Test Register, through the Connect Direct platform, and obtain confirmation of compliance before placing it on the market. That is a positive, checkable listing rather than a claim in marketing copy, and it is the closest thing to a compliance mark that this framework provides. How to check it is here.
The product marking is worth reading too. It must state that notification to the distribution network operator is mandatory both on connection and on disconnection. A product whose packaging is silent on that has not been prepared for the UK framework, whatever else it says.
Where BS 7671 Amendment 4 fits, and where it does not
BS 7671 Amendment 4 was published on 15 April 2026, and it has been widely and wrongly described as the wiring-regulations update that created rules for plug-in solar. It created no such rules. Its headline changes concerned stationary secondary batteries, functional earthing for information and communications technology, Power over Ethernet, and Section 710 for medical locations.
What is true is narrower: the Interim Product Specification cites BS 7671:2018+A4:2026 normatively as the installation standard. We have not identified any plug-in-solar-specific regulation introduced by Amendment 4 itself. So the correct statement is that plug-in solar installations must comply with the current wiring regulations. Amendment 4 was not written for them.
The absence of a standard does not make these devices unsafe
The testing DESNZ commissioned from Arceio Limited, with laboratory partner Eurofins E&E UK, put six commercially available systems through standard 13 A sockets and found stable thermal behaviour, anti-islanding within the required times, and protective devices operating correctly. Its conclusion was that plug-in PV “can demonstrate safe and technically coherent behaviour”.
The same study also found conducted emission exceedances above domestic Class B limits at maximum export, inconsistent export limitation with some devices exceeding their declared ratings, variation in threshold behaviour at extended voltage and frequency limits, a cable sheath that shrank under prolonged high temperature, and one RCBO trip time of 89 ms against a 40 ms standard. Its own summary was that “product quality is not uniform across the market”. We have gone through the findings in detail.
That is the situation a mature standard exists to fix, and the reason the industry bodies (the ECA, Electrical Safety First, the IET, NICEIC and SELECT) issued a joint statement on 9 June 2026 urging the government to move carefully, citing inconsistent product standards and unsafe imports among their concerns.
The practical position
Plug-in solar in Great Britain is governed by a statutory instrument that points at a departmental interim specification adapted from a German pre-standard, with the market policed by a register rather than a certification mark. That framework is workable. It is a different thing from a British Standard, and a seller who blurs the difference is telling you something useful about themselves.
For the rest of the legal picture, covering the 800 VA cap, the battery exclusion, the one-device-per-household limit and G98 notification, start with our explainer on what became legal on 27 August 2026, or the fuller legal rules guide.