The IET published BS 7671 Amendment 4 in April 2026. For the first time in UK electrical regulation, sub-800W solar systems can connect to standard domestic sockets without a qualified electrician. The UK is now, in regulatory terms, where Germany was in 2023. It took a while.
Amendment 4 updates two key chapters. Chapter 702 introduces rules for electrical energy storage systems — directly relevant to plug-in kits with integrated batteries. Chapter 708 updates the framework for connecting generation equipment to domestic circuits. Together they turn plug-in solar from a legal grey area into a fully permitted activity, subject to appropriate product certification.
What exactly changed
Before Amendment 4, connecting solar generation equipment to a UK domestic circuit required a CPS-registered electrician to install a dedicated circuit. This made plug-in solar technically possible but practically expensive — adding £250–£450 to the cost of a kit that might retail at £419. The government announced the regulatory overhaul in March 2026, with Amendment 4 the first concrete step to complete.
Under Amendment 4, a UKCA-certified sub-800W system connected to a standard 13A socket is compliant without an electrician — provided the system carries appropriate product certification. That certification is the BSI product standard, expected July 2026. Which is why the kits aren't on shelves yet.
What Amendment 4 doesn't change
Amendment 4 does not by itself make certified kits available in UK shops. That requires the separate BSI product standard. Until then, the most compliant route remains a CPS-registered electrician on a dedicated circuit. Both steps are needed before truly plug-and-play retail sales happen at scale — as Germany's rollout showed, the regulatory framework is just the starting point. The product availability is the other half.
What this means if you want to install now
The safest current route remains using a registered electrician. This future-proofs your install, satisfies any DNO requirements, and some energy suppliers will ask for confirmation of professional installation if you ever apply for a Smart Export Guarantee tariff. If you're comfortable with the current grey area and want to self-install, the safety case for a certified product on a standard socket is solid. Just know where you stand. For a full breakdown of available kits, see our best plug-in solar kits guide.
