Smart plugs for Home Assistant in the UK and US (2026 guide)
How to choose a smart plug for a UK (Type G, 230V, 13A) or US (Type A/B, 120V, 15A) home: Zigbee vs Wi-Fi vs Matter, energy monitoring, certification and Home Assistant set-up.
The smart plug is the easiest first smart home device, but it is also the one where the country matters most. A plug designed for French or German sockets (Type E/F) is the wrong product for a UK or US home. This guide explains what to check.
1. UK vs US: the electrical basics
| United Kingdom | United States | |
|---|---|---|
| Socket | Type G (BS 1363) | Type A/B (NEMA 1-15 / 5-15) |
| Voltage | 230 V, 50 Hz | 120 V, 60 Hz |
| Typical max load | 13 A (fused plug), about 3,000 W | 15 A circuit; most smart plugs are rated 15 A, about 1,800 W |
| Markings to look for | UKCA (or CE), BS 1363 compliance | FCC ID for the radio; UL or ETL listing for safety |
Always check the rated load printed on the plug before connecting a heater, kettle or space heater, and avoid daisy-chaining plugs.
2. Zigbee, Wi-Fi or Matter?
| Type | Pros | Cons | Choose it if |
|---|---|---|---|
| Zigbee | local, low power, acts as a mesh repeater | needs a Zigbee coordinator | you run Home Assistant with a Zigbee dongle |
| Wi-Fi | no hub, quick app set-up | busier Wi-Fi, often cloud-dependent | you’re just starting |
| Matter (over Wi-Fi or Thread) | works with Apple Home, Google Home, Alexa, SmartThings and Home Assistant | check the Matter logo and version on the box | you want to avoid lock-in |
3. What to check on the spec sheet
- Energy monitoring (W, kWh): useful to spot standby power and to trigger “washing machine finished” alerts.
- Rated load: 13 A in the UK, usually 15 A in the US.
- Local control: can it work without the maker’s cloud? Shelly, most Zigbee plugs and Matter plugs can.
- Physical button and LED: handy for guests; check that the LED can be turned off in a bedroom.
4. Example: Shelly plugs
Shelly sells its plugs in local versions (UK Type G, US Type A/B, EU), with Wi-Fi, local control and Home Assistant integration. Choose your country version from the Shelly smart plug range. For hard-wired lighting, the Shelly 1 Gen4 relay accepts 110–240 V AC and switches up to 16 A at 240 V (Shelly knowledge base), so one model suits both countries. It must be installed behind a switch by someone qualified, in line with UK (Part P) or US (local code) rules.
5. Adding a plug to Home Assistant
- Zigbee plug: in Home Assistant, open the ZHA or Zigbee2MQTT integration, choose Add device, then hold the plug’s button until its LED flashes.
- Wi-Fi plug: set it up on your network with the maker’s app, then add the matching integration (Shelly is discovered automatically on the local network).
- Matter plug: scan the Matter QR code from the Home Assistant companion app.
6. Two useful automations
- Washing machine finished: when power drops below a few watts for two minutes, send a phone notification.
- Kill standby at night: switch off the TV corner at midnight, back on at 7 am.
Getting started from scratch? Read smart home for beginners.
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