Electrical wiring in the United Kingdom

Electrical wiring in the UK refers to setups in buildings like homes, offices, and factories for using electricity. This also includes special places like marinas. But it doesn't include sending electricity over long distances. These setups differ based on factors like voltage, phase, cable type, and circuit design.^[1]

Rules for electrical wiring safety are overseen by regulations like the Building Regulations 2010 and the Electricity at Work Regulations 1989. These rules specify standards for things like wiring. The specific guidelines are found in BS 7671 Requirements for Electrical Installations (IET Wiring Regulations), currently in its 18th edition.

Wiring colours

As of 2006, the standard wiring colors in the UK are the same as in the rest of Europe, following the international standard IEC 60446. This color pattern was initially used for appliance cords in the UK in the early 1970s. However, the original red/black color scheme recommended by the IEE for permanent wiring was used until 2006, though a change to a green/yellow striped wire for grounding was made in 1976. The international standard blue/brown scheme is now commonly seen in most appliance cords. In permanent wiring, the blue/brown arrangement is only present in newer installations after 2004, and the old IEE red/black scheme is likely to continue in existing installations for many more years.^[2]^[3]^[4]

		Pre-1977 IEE	Pre-2004 IEE	Current IEC
Protective earth (PE)
Neutral (N)
Single phase	Line (L)
Three-phase	L1
	L2
	L3

The standard colours in fixed wiring were harmonised in 2004 with the regulations in other European countries and the international IEC 60446 standard. For a transitional period (April 2004 – March 2006) either set of colours were allowed (but not both), provided that any changes in the colour scheme are clearly labelled. From April 2006, only the new colours should be used for any new wiring.