Southern Company is an American gas and electric utility holding company based in the southern United States. It is headquartered in Atlanta, Georgia, with executive offices also located in Birmingham, Alabama. The company is currently the second largest utility company in the U.S. in terms of customer base. Through its subsidiaries it serves 9 million gas and electric utility customers in 6 states. Southern Company's regulated regional electric utilities serve a 120,000-square-mile (310,000 km2) territory with 27,000 miles (43,000 km) of distribution lines.