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Big Six Energy Suppliers

Great Britain's main energy suppliers

The Big Six were Great Britain's largest retail suppliers of gas and electricity, who dominated the market following liberalisation in the late 1990s. By 2002, six companies – British Gas, EDF Energy, E.ON, RWE npower, Scottish Power and SSE – had emerged from the 15 former incumbent monopoly suppliers (the 14 regional public electricity suppliers and British Gas). In 2008, the Big Six still had over 99% of domestic and small business customers.2 Wikipedia text CC BY-SA 4.0

Last updated Oct 21, 2026.

Overview

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The Big Six were Great Britain's largest retail suppliers of gas and electricity, who dominated the market following liberalisation in the late 1990s. By 2002, six companies – British Gas, EDF Energy, E.ON, RWE npower, Scottish Power and SSE – had emerged from the 15 former incumbent monopoly suppliers (the 14 regional public electricity suppliers and British Gas).2

The story

2021–2022

Sharp increases in wholesale gas prices in summer and autumn 2021, and a consequent increase in wholesale electricity prices, led to further collapses. High prices continued into 2022. Ofgem continued to arrange for customers of those companies to be transferred to other suppliers, but when Bulb Energy failed in November 2021 a different approach was needed: with 1.7 million customers, it was the seventh biggest supplier company. Bulb was placed in "special administration" and the UK government undertook to cover its losses while a sale or restructuring was organised, with a potential cost to taxpayers of £1.7 billion.

2023–2024

No significant company failures.

From Wikipedia’s article on Big Six energy suppliers, shared under CC BY-SA 4.0.3

Sources

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