The Big Six Energy Suppliers

The latest Ofgem figures show that at the end of Q2 2020 there were 58 active licensed suppliers in the domestic energy retail market. This number includes those supplying domestic electricity, gas, or both, to homes across the UK.

The amount of licenced energy suppliers in the UK can fluctuate month to month, and where the number of continuing suppliers looks to stay steady, there has been an increase in supplier exits over the last four quarters. Some of the reasons suppliers are going bust are due to increases in wholesale costs, network costs, and additional charges due to government obligations.

And, even though there is a wide variety of companies out there, each with specific tariffs, price ranges and unique selling points, the market is currently dominated by six large energy suppliers.

Who were the big six energy suppliers?

Regularly referred to as the 'Big Six' the six largest energy suppliers are companies that supply most of the energy to domestic households in the UK. With 72% market share between them, they supply gas and electricity to over 50 million homes and businesses in Britain. They are:

British Gas - British Gas is the leading big six energy supplier with the largest profits. They are owned by parent company Centrica plc who also own Scottish Gas and Nwy Prydain. They supply energy to over 12 million homes.

EDF Energy - EDF Energy are a UK subsidiary of French state-owned company, Electricite de France and are the best provider for low-carbon, environmentally friendly energy. They currently provide energy to around 5 million customers.

E.ON - With around 3.8 million customers in the UK, E.ON are one of the leading energy providers for Britain. The company also operated in over 30 countries and has amassed nearly 30 million customers overall.

nPower - Recently becoming part of the E.ON group, nPower serves around 3.6 million accounts with electricity and gas.

ScottishPower - Part of the Iberdrola group, and a world leader in wind energy, ScottishPower makes up one of the largest energy companies in the world. Their UK sector supplies gas and electricity to over 5 millions customers.

SSE - The company became part of the OVO family in 2020, with the latter company owning other energy suppliers: Boost, Spark Energy and OVO Energy. Together, they supply energy to almost 5 million households across the UK.

Are the big six the cheapest energy suppliers?

Even though they dominate the market, and are well-known names, this doesn't necessarily mean the Big Six are your best bet when it comes to energy rates.

They may attract customers with cheap onboarding tariffs but these normally expire after a certain period. Once this cheaper stage has ended, these companies may automatically roll you onto more expensive energy tariffs.

Is there an alternative to the Big Six?

Ofgem research shows that between 2011 and 2020, the combined electricity market share of the six large suppliers dropped from almost 100% to 72%

This trend could be set to continue as smaller and medium sized energy suppliers are starting to offer not only better rates, but better customer service and unique propositions, such as green energy sources.

Another big concern for customers for not switching used to be that smaller or medium suppliers could go bust leaving them without energy . This is simply not the case if your own supplier were to go under as Ofgem will supply an intermediary provider until, a new one is secured, meaning your energy use is not affected.

Should I switch energy supplier?

The latest State of the Energy Market report from Ofgem shows that the number of unengaged customers is still high, and those who are unengaged are more likely to be on an expensive default tariff and paying over the odds.

The number of customers who have never switched supplier or have only switched once has decreased from 61% to 49% since 2018 but that's still a high proportion of people who could be saving money by switching energy supplier.