Caution
A plug socket in your home has stopped working: nothing happens when you plug something in.
A plug socket is loose on the wall and moves or wobbles when you plug something in or pull a plug out.
High risk
The plastic faceplate of a socket is cracked, broken, or has a piece missing, exposing the interior.
Low risk
The USB charging ports built into your wall socket have stopped working, even though the main plug sockets are fine.
The external socket on the outside wall of your house has stopped working.
One or more sockets stopped working after a power cut or outage and have not come back on.
One side of a double socket not working usually means one half of a UK twin outlet has lost power while the other half still works. In kitchens and bedrooms that often shows up after heavy use: kettle on one side, toaster or phone charger on the other, then suddenly only one plug gets live. Common causes are a loose terminal, a failed contact behind the faceplate, a damaged pin aperture, or a break on the strap that feeds both sides. Picture a neighbour’s worktop at breakfast: left socket dead, right socket fine, nobody sure whether it is safe to keep using the live half. Unplug both sides, stop if you smell burning or see scorch marks, and book an electrician rather than poking inside the faceplate with the circuit still live.
The white plastic faceplate of your socket has turned yellow, brown, or has dark marks around the plug holes.
Describe the job and get a fixed price from a local electrician.