<P> Area code 203 is a North American telephone area code that is assigned to the southwestern part of Connecticut , and is overlaid with area code 475 . The numbering plan area ( NPA ) 203 originally covered the entire state of Connecticut when the North American Numbering Plan was created in 1947 . Today the numbering plan area stretches from Connecticut 's western border , along its southern coast , to Madison , and north to Meriden . The region encompassed by 203 and 475 roughly corresponds to the Connecticut side of the New York metropolitan area . </P>
where does the area code 475 come from
the Connecticut side of the New York metropolitan area