How to Replace a Double Socket UK (+ USB Upgrade)

Replacing a worn or dated double socket — or upgrading it to one with built-in USB charging — is a straightforward like-for-like swap when done methodically. Here's the safe sequence, the wiring layout, and what to check before you buy.

Safety first: Isolate the socket circuit at the consumer unit and prove dead with a voltage tester before removing the faceplate. Like-for-like replacement is generally non-notifiable in England and Wales, but all work must meet BS 7671. If in doubt, use a qualified electrician.

Before you start: what's behind the plate?

UK socket circuits are usually a ring final (two cables in the back box) or a radial/spur (one cable). You may find one, two, or occasionally three cables — reconnect them all exactly as found. Photograph the terminals before disconnecting.

Wiring diagram: socket rear terminals (UK colours)

Double socket — rear viewNELCable 1 (ring)Cable 2 (ring)Brown → LBlue → NEarth → E(green/yellow sleeved)
Ring final shown (two cables). A spur has one cable; wire the single set the same way. Old colours: red = live, black = neutral.

What you'll need

  • Replacement socket — browse double sockets or USB sockets
  • Insulated screwdrivers and a voltage tester
  • Brown/blue sleeving if old colours (red/black) are unsleeved

Step-by-step

  1. Isolate. Turn off the correct MCB/RCBO, then plug in a lamp or tester to confirm the socket is dead.
  2. Remove the faceplate. Unscrew and ease it forward; test L, N and E terminals to prove dead.
  3. Photograph and disconnect. Note how many conductors sit in each terminal. Keep pairs together.
  4. Reconnect. Live (brown/red) to L, neutral (blue/black) to N, earth (green/yellow, sleeved) to E — all conductors fully seated, screws tight, no exposed copper.
  5. Earth the plate. Metal faceplates need the earth connected to the plate terminal as well as the back box.
  6. Refit and test. Fold cables neatly, screw home without pinching, restore power, and test with a socket tester.

Upgrading to a USB socket: two checks

  • Back box depth. USB sockets have deeper internals — most need a 25mm minimum, 35mm ideally. See our back box guide.
  • A or C ports. USB-C now charges phones, tablets and laptops fastest. Our USB-A vs USB-C guide covers which to fit; hotels typically fit one of each per bedside.

Choosing the replacement

All BG ranges fit standard UK boxes: Nexus Metal, Nexus Screwless and Evolve — with matching USB options in every finish. Buying for a refurb? Multi-buy savings apply automatically, and our trade account adds project pricing.

FAQs

Can I replace a socket myself in the UK?

Like-for-like replacement (including USB upgrades on the same circuit position) is generally non-notifiable DIY work in England and Wales, done competently to BS 7671. New spurs or new socket positions are a different matter — use an electrician.

Why does my new socket not sit flush?

Usually a shallow back box or unfolded cables. Deeper-frame plates (USB, screwless) need 25–35mm boxes; fit a deeper box or a spacer.

Do USB sockets draw power when nothing is plugged in?

Modern ones draw negligible standby power — typically under 0.1W — and switch off their charging circuitry when idle.