Things to think about

If you are in any doubt about working with electricity, seek professional advice from a qualified electrician. Any electrical work must comply with the Institution of Electrical Engineers (IEE) regulations (BS7671).

Always refer to and follow precisely the manufacturer’s instructions when fitting a new socket.

Any electrical installation must comply with Building Regulations, specifically Part P, which came into effect on 1 January 2005, with the ammended version coming into effect on 6 April 2006. A further update came into force on 6 April 2013. Refer to these regulations before carrying out any electrical work (download at

Replacing a socket is nonnotifiable under Part P, and therefore it is not necessary to have the work carried out by a qualified electrician, or to inform your local authority building inspector of the work, except in high-risk areas, or special locations, such as bathrooms. For a full list of these locations, refer to Part P. Part P strongly advises taking advice from a qualified electrician for carrying out any DIY electrical work. All electrical work must be tested and inspected.

This guide shows fitting a metal socket onto a plastic flush mounting box and the instructions shown overpage only relate to plastic mounting boxes. If you have metal mounting boxes, earthing requirements may vary, so refer to the manufacturer’s guidelines.

If the socket you are changing has two earth terminals, this means that it has a dual earth facility, which is required if you need to comply with Regulation 607 of BS7671. As always, follow the manufacturer’s guidelines and recommendations in such instances.

If you find earth wires are bare, you must sheathe them with some green and yellow sleeving.

Colours used in hard-wire installations (including cables supplying sockets) have changed in recent years. The table below shows the different colours for wires, prior to and after April 2004.

  Pre April 2014 Post April 2014

The information in this guide shows post April 2004 wiring.

Change a socket


Before carrying out any work on the socket, ensure that the mains electricity supply is turned off at the consumer unit.




Unscrew the retaining screws on the socket in order to release it from the socket mounting box.




Gently ease the socket forward to reveal the socket wiring behind the outlet.




Commonly you will find three wiring configurations. This shows a single cable connected at the socket, so you will have one wire of each colour.




Alternatively, you may find two cables connected at the socket, so you will have two wires of each colour.




Finally, you may find three cables connected at the socket, so you will have three wires of each colour.




For whichever configuration, unscrew the terminal screws to release all the wires: brown = live, blue = neutral, green and yellow = earth.




Position the new socket and note where the live (L), neutral (N) and earth (E or earth symbol) terminals are located.




Insert the blue wire(s) into the neutral (N) terminal, brown into the live (L) terminal and green and yellow into the earth (E or earth symbol) terminal.




Make sure that only bare wire goes into the terminal, and no bare wire is visible. Ensure screws are tightened securely onto copper cable cores.




Gently press the socket back in place over the mounting box, taking care not to trap any wires between the socket and the wall.




Fix in place using the retaining screws provided. Do not overtighten. Use a spirit level to make sure the socket is level. Restore power and test.

What you’ll need:


Green and yellow sleeving (if required)


Small spirit level

Combination pliers