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
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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.