Big 6 energy companies: who are the biggest suppliers - and how the gas price crisis has changed market share

British Gas remains the largest supplier of gas in Great Britain, though its share of the market has reduced steadily

Rising wholesale prices of gas has already seen 10 energy companies go bust in recent weeks, with more expected to follow before the end of the year.

Industry experts have warned that smaller suppliers are at risk while it is understood the bigger companies have the means to absorb the immediate financial strain.

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Household names such as British Gas and E.On have already taken on some of the accounts from those energy providers to have already bitten the dust amid the gas crisis.

But with reports of the number of energy suppliers falling from 70 at the start of 2021 to as few as 10 the traditional industry heavyweights are likely to see their market share increase.

Here’s a look at the most recent data on each company’s market share of gas supply in Great Britain and how recent events could reshape the industry, with many smaller providers at risk.

Who are ‘the big 6’ energy companies?

Since privatisation of the gas sector, six companies have historically always commanded a large share of the supply market in Great Britain.

These well established energy suppliers are often referred to as ‘the big 6’.

They are the biggest energy providers and have been dominant in the sector for some time - but they are not adverse to change with many mergers taking place.

Traditionally, the big six were British Gas, EDF Energy, E.ON, npower, Scottish Power and SSE.

Though SSE is owned by OVO, npower is owned by E.ON and Scottish Power is owned by Iberdrola and not all the companies supplying gas to Britain are based in the UK.

Smaller companies, particularly those with an emphasis on renewable energy, have enjoyed an increased market share in recent years, including Bulb and Octopus.

Gas supply domestic market share by company. (Graphic: Mark Hall / JPIMedia)

How much of the gas supply market do they command?

British Gas remains the largest supplier of gas in Great Britain, though its share of the market has reduced steadily from 56% in 2005 to less than half that in 2021.

Data sourced from Ofgem, the industry’s independent regulator for Great Britain, shows British Gas holds a market share of 26.6% in the latest figures (dated July 2021).

Gas supply % market shares by company: Domestic (GB)

  • British Gas - 26.6
  • E.On - 14.3
  • Ovo - 11.8
  • EDF - 9.2
  • Scottish Power - 7.8
  • Small suppliers - 7.5
  • Octopus Energy - 7.1
  • Bulb Energy - 5.1
  • Shell Energy - 3.6
  • Utilita - 2.7
  • Avro Energy - 2.4
  • Utility Warehouse - 2

Which companies are at risk of going bust amid gas crisis?

With rising wholesale costs of gas, energy companies have had to shoulder the financial strain in the short term due to the industry’s price cap.

The energy price cap, currently £1,138 a year but set to rise in October, is the maximum most households pay for gas on standard tariffs.

If you use more than this, then you will still have to pay for what you use.

Smaller companies offering cheaper tariffs than competitors have been hit hardest, unable to pass this rise in costs to consumers and limited financial resources.

No fewer than 10 companies have gone bust in recent weeks - Igloo Energy, Symbio Energy, Enstroga, Avro Energy, Green Supplier Limited, Utility Point, People’s Energy, PFP Energy, MoneyPlus Energy and HUB Energy.

New suppliers have been found for six firms to have gone bust, with industry regulations ensuring energy supply will continue for affected customers.

EDF Energy has taken on Utility Point customers, while British Gas is the new supplier for People’s Energy, PFP Energy and MoneyPlus Energy accounts. E.ON is the new supplier to HUB Energy accounts.

Why are gas prices soaring?

A combination of factors have resulted in a sharp rise in wholesale gas prices, with a price increase of 250% since the start of the year.

Experts have put soaring prices down to a cold winter, which saw most people stay indoors due to Covid lockdowns, reducing global supplies.

While maintenance work, a lower output from renewable wind and solar sources and outages at nuclear power stations have also contributed.

It has created a perfect storm as the UK prepares itself for the winter months, when demand for gas is at its highest as households put the central heating on.

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