The US Area Code System
The United States area code system is a numerical framework employed to organize and manage telephone numbers across different geographic regions. Introduced in 1947 by AT&T and the Bell System, the system divides the U.S. into distinct Numbering Plan Areas (NPAs) and is managed by the North American Numbering Plan Administration (NANPA).
Numbering Plan Areas (NPAs)
Each Numbering Plan Area (NPA) area, also know as Area Codes, represented by a unique three-digit code. The area code format is commonly presented as "(XXX)", where XXX denotes the three-digit numerical identifier, followed by a three-digit NXX Prefix and a four-digit Line number. This gives you an (NPA)-NXX-XXXX or NPA NXX XXXX phone number format.
Click any state on the map to discover its area codes, which cities they cover and more.
US Area Codes
View a list of all area codes, arranged by groups, by clicking on their tab below.
Area Code Lookup