XXX Exchange code 3 digits
XXXX Line number 4 digits
Area Code
The area code USA Phone Number is a unique threedigit number that identifies a specific geographic region within the United States. It serves as a routing code directing calls to the appropriate local network. For example the area code for New York City is 212.
Exchange Code
The exchange code also known as the central office code is a threedigit number that further identifies a specific telephone exchange within an area code. For instance the exchange code 555 may belong to an exchange located in Manhattan New York City.
Line Number
The line number is a fourdigit number that uniquely identifies a particular telephone line within an exchange. This number is assigned by the telephone company and is unique to each line.