Centrica originates from British Gas plc, which was formed as a result of the privatization of the British Gas Corporation in 1986. It was 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 itself retained the British Gas brand, allowing it to provide gas and electricity to residential and business customers in the UK.
British Gas is 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 fourth quarter of 2019, British Gas received 1,092 complaints per 100,000 customers. This was the lowest complaint rate among its competitors.
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 country.