The undermentioned are the main participants in the U.K. energy markets.

British Gas plc - The original publicly owned Gas Utility, which was privatised as Centrica and retails gas within the UK.

BG Group – the other half of the publicly owned Gas Utility which was privatised – this part conducts gas and oil exploration and operates world-wide using the British Gas brand name outside the UK

Ofgem – the Office of Gas and Electricity Markets, is the independent regulator of the gas and electricity industries.

Energywatch - a government agency, which acts on behalf of the consumer as an independent watchdog for the gas and electricity industry.   Switching sites can apply to its code of conduct.

EDF - the French state owned utility which bought into the UK and operated as London Electricity, SWEB and Seeboard

Eon - the largest German utility which operates under the Powergen brand plus Norweb, East Midlands and Eastern

RWE - another German utility, which operates as Yorkshire, Northern and Midlands Electricity

Electricity Association – The representative body of the major UK electricity companies