Area Code 203 History:
Area code 203 was put into service 01/01/1947. In 1995 Area code 203 was split to form area code 860. In 2009 area code 203 was overlaid with area code 475.
Counties in Connecticut within area code 203 include:
New Haven, Fairfield and Litchfield.
Major cities or places in Connecticut within area code 203 include:
Area codes 203 and 475 serve the southwestern portions of Connecticut including the larger communities of Bridgeport, Danbury, Darien, East Haven, Meriden, Milford, Naugatuck, New Haven, Norwalk, Orange, Shelton, Stamford, Trumbull, Waterbury, West Haven and Westport in addition to many smaller communities.