Is plug-in solar legal in the UK? (2026)
Yes — in force since 15 April 2026 BS 7671 Amendment 4 Updated: 15 June 2026
Legalisation timeline
| Date | Milestone | What it means for you |
|---|---|---|
| 16 March 2026 | BS 7671 Amendment 4 ratified by the IET | Industry signal: the rule change is final. No live effect yet. |
| 15 April 2026 | Amendment 4 in force | ≤800W microgeneration is now classed as a portable appliance, provided safety requirements are met. |
| ~ July 2026 expected | BSI product standard for DIY plug-in kits | This is what unlocks true plug-and-play DIY. Manufacturers can certify against a UK-recognised standard. |
| ~ October 2026 expected | End of transitional period | By this point the legal and product-standard picture should be coherent end-to-end. |
Dates after July 2026 are based on publicly stated expectations and may shift. We update this page when they do.
What Amendment 4 actually changes
Amendment 4 to the IET’s 18th Edition Wiring Regulations (BS 7671) does one specific, narrow thing: it reclassifies a compliant microgeneration unit up to 800W as a portable appliance, rather than a permanent generation installation requiring Part P notification and a full Electrical Installation Certificate.
For that reclassification to apply, the unit must meet all of:
- 800W AC inverter output cap (not panel watts — you can have higher-rated panels behind a clipping inverter).
- Single-phase connection.
- Type-approved anti-islanding inverter — the inverter must disconnect within ~0.2 seconds when grid voltage drops, so it cannot energise a dead grid (protects line workers).
- RCD protection on the final circuit it connects to.
What Amendment 4 does not do: create a product standard for off-the-shelf plug-in kits. That part is BSI’s job and is the next dependency.
What is legal in your flat today
As of June 2026, here is the honest picture — broken down by install path.
✅ 800W hardwired install by a CPS-registered electrician
This is the cleanest, fully-compliant route available today. The electrician fits the microinverter, isolator and protection in line with Amendment 4, certifies under Part P, and you (or they) file a G98 Connect & Notify with your DNO. Typical professional installation cost: £300–£600 on top of kit price.
❗ True plug-and-play DIY kit
Legally possible under Amendment 4 if the kit is certified to meet the safety requirements above. The blocker today is that no UK product standard exists yet (the BSI one is expected ~July 2026), so very few currently-sold kits can demonstrate compliance to a UK standard. Several manufacturers ship CE/EN-certified kits that meet equivalent European standards — in practice these are likely to be accepted post-July, but if you install one before the BSI standard is published, you are inferring compliance rather than relying on a UK-stamped one.
❌ “Just plug it in” with no DNO notification, no RCD, no anti-islanding inverter
Not legal. The ≤800W “portable appliance” classification only applies when the four safety conditions above are met and the DNO has been notified via G98. Skipping any of those puts you outside Amendment 4’s coverage.
G98 notification — the bit nobody tells you about
The G98 form is a Distribution Network Operator (DNO) notification under Engineering Recommendation G98 (microgenerators up to 16A per phase). For a single-phase 800W install, it is:
- Free.
- Online, takes ~10 minutes.
- Notification, not approval — you tell them what you’ve installed, you don’t ask permission.
- Required for the install to fall within Amendment 4’s portable-appliance pathway.
The form depends on your region’s DNO. We have a step-by-step on the next page:
FAQs
- Do I need planning permission for balcony solar in the UK?
- For most flats: no. Microgeneration up to 800W on a balcony or external wall does not normally require planning permission, but listed buildings and some conservation areas have additional restrictions. Always check with your local planning authority and, for a flat, your leasehold/freeholder.
- Do I get paid for exported electricity (SEG)?
- Generally no, in practice. The Smart Export Guarantee (SEG) requires an MCS-certified install and a smart meter, which most plug-in balcony installs do not meet. Treat all savings as self-consumption only — every kWh your kit makes that your appliances use is a kWh you don’t pay your supplier for, at ~27–28p/kWh under the current price cap.
- What if I rent?
- You need landlord permission. Amendment 4 doesn’t override your tenancy agreement. A polite written request showing the kit is portable, Amendment 4-compliant, and removable without damage is the usual route. Many landlords say yes.
- What if my flat is leasehold?
- Check your lease for clauses about altering the external appearance of the building or attaching anything to the structure. Even a non-permanent install may need freeholder consent. This is the most common UK gotcha.
- How is this different from Germany?
- Germany legalised 800W “Balkonkraftwerk” plug-in solar in 2024 with a product standard (VDE-AR-N 4105) already in place — DIY installs took off immediately. The UK rule change in Amendment 4 is equivalent in spirit, but the product-standard piece is still rolling out (~July 2026), so we are 3–6 months behind on the DIY side.
Sources
- IET — BS 7671:2018+A4:2026 (18th Edition Wiring Regulations, Amendment 4), ratified 16 March 2026, in force 15 April 2026.
- Engineering Recommendation G98 — connection of fully type-tested micro-generators (up to and including 16A per phase) in parallel with public low-voltage distribution networks. Energy Networks Association.
- Ofgem — energy price cap (Q2 2026): residential electricity standing charge and unit rate.
- BSI — product-standard development for plug-in solar (expected publication July 2026).
If you spot a fact on this page that has shifted, let us know — we update.