Area codes 203 and 475 are telephone

area code A telephone numbering plan is a type of numbering scheme used in telecommunication to assign telephone numbers to subscriber telephones or other telephony endpoints. Telephone numbers are the addresses of participants in a telephone network, rea ...

s in the

North American Numbering Plan The North American Numbering Plan (NANP) is an integrated telephone numbering plan for twenty-five regions in twenty countries, primarily in North America and the Caribbean. This group is historically known as World Zone 1, World Numbering Zone ...

(NANP) for the southwestern part of the U.S. state of

Connecticut Connecticut ( ) is a U.S. state, state in the New England region of the Northeastern United States. It borders Rhode Island to the east, Massachusetts to the north, New York (state), New York to the west, and Long Island Sound to the south. ...

. The numbering plan area (NPA) is mostly coextensive with the Connecticut portion of the

New York metropolitan area The New York metropolitan area, also called the Tri-State area and sometimes referred to as Greater New York, is the List of cities by GDP, largest metropolitan economy in the world, with a List of U.S. metropolitan areas by GDP, gross metropo ...

, and comprises most of Fairfield County, all of New Haven County, and a small portion of Litchfield County. When the American Telephone and Telegraph Company (AT&T) established the first nationwide numbering plan in 1947, Connecticut received only a single area code, 203, of the 86 original North American area codes. On August 28, 1995 the state was divided into two NPAs, reducing the area of 203 to today's extent and adding area code 860 for the region outside. Area code 860 was eventually overlaid with 959, and NPA 203 received a second area code when 475 was added on December 12, 2009. This overlay was first proposed by the Connecticut Department of Public Utility Control in August 1999. Even though area code 475 overlays only 203, all callers in Connecticut (including those in area code 860) had to dial all calls with ten digits, effective November 14, 2009;
Planning Letter 388
' NANPA, April 14, 2009 this was in preparation for the overlay of

area code 959 Area is the Measure (mathematics), measure of a Domain (mathematical analysis), region's size on a surface (mathematics), surface. The area of a plane region or ''plane area'' refers to the area of a shape or planar lamina, while ''surface are ...

on area code 860 that was implemented in 2014. The first range of telephone numbers made available in Connecticut's third area code was (475) 882-4xxx, in the Huntington section of Shelton.

Service area

The counties included in the numbering plan area are: : Fairfield (except the Town of Sherman),

New Haven New Haven is a city of the U.S. state of Connecticut. It is located on New Haven Harbor on the northern shore of Long Island Sound. With a population of 135,081 as determined by the 2020 U.S. census, New Haven is the third largest city in Co ...

, and Litchfield (the towns of Woodbury, Bethlehem, and a small part of Roxbury). This serves the following cities and towns: : Ansonia, Beacon Falls,

Bethany Bethany (,Murphy-O'Connor, 2008, p152/ref> Syriac language, Syriac: ܒܝܬ ܥܢܝܐ ''Bēṯ ʿAnyā''), locally called in Palestinian Arabic, Arabic Al-Eizariya or al-Aizariya (, "Arabic nouns and adjectives#Nisba, laceof Lazarus (name), L ...

, Bethel, Bethlehem, Branford, Bridgeport, Brookfield,

Cheshire Cheshire ( ) is a Ceremonial counties of England, ceremonial county in North West England. It is bordered by Merseyside to the north-west, Greater Manchester to the north-east, Derbyshire to the east, Staffordshire to the south-east, and Shrop ...

, Danbury, Darien,

Derby Derby ( ) is a City status in the United Kingdom, city and Unitary authorities of England, unitary authority area on the River Derwent, Derbyshire, River Derwent in Derbyshire, England. Derbyshire is named after Derby, which was its original co ...

, East Haven, Easton, Fairfield,

Greenwich Greenwich ( , , ) is an List of areas of London, area in south-east London, England, within the Ceremonial counties of England, ceremonial county of Greater London, east-south-east of Charing Cross. Greenwich is notable for its maritime hi ...

, Guilford, Hamden, Madison, Meriden, Middlebury, Milford, Monroe, Naugatuck, New Canaan, New Fairfield,

, Newtown, North Branford, North Haven, Norwalk, Orange,

Oxford Oxford () is a City status in the United Kingdom, cathedral city and non-metropolitan district in Oxfordshire, England, of which it is the county town. The city is home to the University of Oxford, the List of oldest universities in continuou ...

, Prospect, Redding, Ridgefield, a small part of Roxbury, Seymour, Shelton, Southbury, Stamford, Stratford, Trumbull, Wallingford,

Waterbury Waterbury is a city in the U.S. state of Connecticut. Waterbury had a population of 114,403 as of the 2020 United States census, 2020 Census. The city is southwest of Hartford, Connecticut, Hartford and northeast of New York City. Waterbury i ...

, West Haven,

Weston Weston may refer to: Places Australia * Weston, Australian Capital Territory, a suburb of Canberra * Weston, New South Wales * Weston Creek, a residential district of Canberra * Weston Park, Canberra, a park Canada * Weston, Nova Scotia * W ...

, Westport, Wilton, Wolcott, Woodbridge, Woodbury The city of Meriden is notable as the only place in Connecticut from where one can call towns in either the Hartford or New Haven exchanges toll-free from a landline telephone.

References

External links

Connecticut Department of Public Utility Control
{{Area code box, State=CT , This=Area codes 203 and 475 , N= 860, 959 , S= 516/363, 631/934 , E= 860, 959 , W= 914, 845/329 , S1=NY Telecommunications-related introductions in 1947 Telecommunications-related introductions in 2009 203 203 Fairfield County, Connecticut New Haven County, Connecticut Litchfield County, Connecticut

Service area

See also

References

External links