Centrica plc is a British multinational energy and services company with its headquarters in Windsor, Berkshire, England. Its principal activity is the supply of electricity and gas to consumers in the United Kingdom and Ireland. It is the largest supplier of gas to domestic customers in the United Kingdom, and one of the largest suppliers of electricity, operating under the trading names British Gas in England and Wales, Scottish Gas in Scotland, and Phoenix Gas in Northern Ireland. It owns Bord Gáis Energy that operates in Ireland. The company also provides household services including plumbing. Centrica is listed on the London Stock Exchange, and is a constituent of the FTSE 100 Index. Wikipedia