A guide to the Big Six energy suppliers

The ‘Big Six’ are the largest energy suppliers in the UK. Find out a bit more about them and see if bigger means better when it comes to choosing where your energy comes from.

The ‘Big Six’ are the largest energy suppliers in the UK. Find out a bit more about them and see if bigger means better when it comes to choosing where your energy comes from.

Peter Earl
From the Energy team
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Posted 13 JULY 2020

Who are the Big Six?

The ‘Big Six’ is the collective name given to the six biggest energy suppliers in the UK. They are:

  • British Gas
  • SSE
  • E.ON
  • EDF Energy
  • npower
  • Scottish Power

Collectively, the Big Six supply gas or electricity to approximately 79% of homes in the UK.

They’ve been pretty dominant since the government passed the Electricity Act in 1989, which allowed privatisation in the energy industry, although there have been various mergers and break ups since then.

Your guide to the Big Six energy suppliers

British Gas is the UK’s largest energy supplier, warming 11 million homes with gas and lighting up six million with electricity.
SSE is the second largest UK supplier, with nearly nine million customers. You might know it better as Scottish and Southern – a previous brand – or Southern Electric, Scottish Hydro, SWALEC and Atlantic – current brands under SSE.

E.ON previously known as Powergen, E.ON powers seven million households in the UK and has a strong focus on innovation.

  • EDF Energy provides energy to around six million homes and is the UK’s largest provider of low-carbon electricity. You might also know the company as its previous brands; SEEBOARD, SWEB energy & London Electricity.EDF has a French parent company the EDF Group.
  • npower supplies five million UK homes with gas and electricity. It previously operated under the brand names Innogy, Northern Electric and Yorkshire Electricity.
  • Scottish Power also provides energy to five million homes in the UK. It started as Clyde Valley Electrical Power Company, then became SSEB (South of Scotland Electricity Board), and now is owned by Spanish energy firm Iberdrola.

Is it a good idea to stick with one of the Big Six?

The Big Six aren’t always the cheapest option when comparing energy prices, although bigger companies can sometimes afford to be more competitive with their pricing.  

Energy is energy. Regardless of who you buy it from, it will come to your pipes and switches the same way. Which provider you choose is all down to personal preference, cost and customer service.

The Big Six are big because they have the most customers – but much of this is due to how long they’ve been around for, or which companies they’ve merged with, rather than because they deliver the best service and prices. These days more of our customers seem to be switching away from the Big Six rather than to them. See who the biggest winners and losers are in switching in our monthly Energy Snapshot.

See our Energy Snapshot

How do I find an alternative to the Big Six?

If you don’t want to go with one of the Big Six, there are plenty of other options, so don’t worry about going against the majority. In December 2019, the favourite smaller energy suppliers that customers switched to through Compare the Market included:

  • Bulb
  • ESB energy
  • Igloo energy
  • Utility point
  • So Energy
  • Green Network Energy
  • GOTO energy
  • Bristol Energy Limited

In our top 20 of most switched to suppliers, smaller numbers also switched to:

  • Ovo Energy
  • Simplicity Energy
  • Zebra Power
  • Pure Planet

Some are dedicated to sustainable sourcing and green energy, so if you’re looking for an eco-friendly supplier, there are plenty of options.

How do I switch energy providers?

Whether you’re moving to or from one of the Big Six providers, changing gas and electricity supplier is simple with Compare the Market. You’ll just need to have your latest bill to hand and tell us where you live. Why not start a quote online today and see if you could start saving?

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