Can I install smart switches without a neutral wire?
Quick answer
Some smart switches work without a neutral wire, but most require one. Check your switch wiring before buying — older UK wiring often lacks a neutral at the switch.
🏠Homeowner view
Most smart light switches need four wires: live, neutral, earth, and the switch wire. The problem in many UK homes is that older wiring only brings a live and switch return to the switch — no neutral. Without a neutral wire, the switch can't power itself (it needs a tiny amount of electricity to run its electronics when the light is off). There are two solutions: smart switches that work without a neutral (Shelly 1, some Philips Hue switches) — these work by letting a tiny current trickle through the light bulb, but can cause LEDs to flicker or glow dimly. The better solution is to run a new switch cable with a neutral, which requires an electrician. If your switch back box has a neutral wire already (common in loop-at-switch wiring or new builds), most smart switches will work fine. Check by carefully removing your switch faceplate — a neutral wire will be blue (or black in old wiring) connected to the switch itself.