British Gas plc was formed as a result of the privatization of the British Gas Corporation in 1986, one of many privatizations brought about during the time Margaret Thatcher served as British Prime Minister. Further changes took place in 1997, with British Gas undergoing a demerger to form Centrica and BG plc. Centrica retained the British Gas brand, allowing Centrica to provide gas and electricity to residential and business customers in the UK.
British Gas are one of the so-called ‘Big Six’ energy suppliers in the UK, the group of energy suppliers that enjoy the greatest share of the UK's energy market. During the final quarter of 2015, British Gas received the fewest complaints per 100,000 customers of any of the Big Six suppliers.
Within the UK, Centrica provides energy services under three business sectors; UK Home, UK Business, and Ireland. UK Home accounts for the vast majority of the overall customer base, reporting 21.8 million customer accounts in 2016.
Like many of the larger suppliers, Centrica have endured declining profits in recent years. This is attributed to changing product mixes, the improved ease with which consumers can compare tariffs, and that the practice of switching energy suppliers has become more common in the UK.