I’ll start this page with a warning: Obviously, if you’re not a competent person, you shouldn’t be attempting any type of work on electrical wiring. It’s better to be safe than sorry, especially if the wiring in your home is old as the circuit breakers may not be effective as those found in modern buildings.
However, there are occasions when a homeowner or DIYer will come across wires or cables that are of different colours and it’s always prudent to be knowledgeable about which wire does what.
The guide below is for UK (British) electrical wiring, if you live in another country, the colours may be different.
The Old System
Prior to “harmonisation” with other European countries, the United Kingdom’s electrical wiring system used:
Red – live
Black – neutral
Green/yellow – earth (sometimes bare wire without a sleeve)
Here’s an image:
Old UK Electrical Wiring Colours
The New System
The new system ensures that all new wiring installations in the UK are fully harmonised with other countries in the European Union.
This obviously has several advantages, including safety, as EU citizens are currently allowed to work in any other EU country and even after Brexit, we still have plenty of mainland Europeans living and working in the UK.
The new UK wiring system comprises of:
Brown – live
Blue – neutral
Green/Yellow – earth
Here’s a photo:
New UK Wiring Colours
When Did The Colours Change?
The new harmonised wiring colour system was made mandatory in 2006, although it was optional for several years prior to this date.
If your home was constructed prior to this date, it will probably contain the old wires.
If you’ve had an extension completed, your home may contain both systems, although if this is the case, a warning notice should be placed on the consumer unit to warn you and anyone working on the wiring. This is to avoid confusion.
Here’s a side by side image showing the two different types of wiring:
UK Electrical Colour Wiring Diagram
A Simple Rhyme to Remember
If like me, you’re a bit forgetful, try this rhyme to help jog your memory:
Touch red and you’ll be dead.
Touch brown and you’ll go down.
Other Cable Colours to be Aware of
Just to confuse matters, there are other cables in the UK that have similar colours to the mains electrical wiring:
TV aerial cables do not carry any voltage but many are brown in colour – the same colour as the new “live” wiring in the UK.
Many satellite and cable tv customers will have a black cable going into the back of the tv, the same colour as the old neutral wire.
If you’re in doubt, call a sparky.
Electrician’s Prices
The team here at Job Prices has done extensive research into how much it costs to replace a consumer unit or even rewire an entire house:
Consumer units are often called fuseboxes and they contain circuit breakers so the power is cut off when there’s a surge of electricity. This protects those in the home from shocks and electrical fires. See how much it costs to replace consumer units/fuseboxes here.
House rewires are a mammoth task and it’s often easier to move out of the home while the work is being done. Check out our house rewire price guide here.
If you need an electrical safety report, which is often referred to as a certificate, to prove your house is safe, check out our guide to electrical safety certificates.
Schemes and Registers
This website lists all the electricians that are part of the “Competent Persons” schemes in the UK. This is a good place to start when searching for a suitable electrician in the UK.
The NICEIC is the UK’s leading voluntary regulatory body for the electrical industry. You can look up electricians via their site.
Get a Quote From a Pro
If DIY isn’t your strong point, hit the button below to see how we can help:
This guide was written by Danny Woodley and was last updated in April 2022.
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