British Gas is an energy and home services provider in the United Kingdom. It is the trading name of British Gas Services Limited and British Gas New Heating Limited, both subsidiaries of Centrica.Serving around twelve million homes in the UK, British Gas is the biggest UK energy supplier and is considered one of the Big Six dominating the gas and electricity market in the United Kingdom. The British Gas Corporation was privatised as British Gas plc by the Thatcher government and on 8 December 1986 its shares were floated on the London stock market. Centrica trades as Scottish Gas in Scotland.