What is what area code is 203?

Area code 203 serves the southwestern portion of the state of Connecticut in the United States. It covers major cities like New%20Haven, Bridgeport, and Stamford. It was one of the original area codes created in 1947. Due to increasing demand for phone numbers, area code 475 was introduced as an overlay to the 203 region in 2009. This means that within the 203 area, ten-digit dialing is required.