Ads
related to: phone number exchange code lookup
Search results
Results From The WOW.Com Content Network
Telephone numbers listed in 1920 in New York City having three-letter exchange prefixes. In the United States, the most-populous cities, such as New York City, Philadelphia, Boston, and Chicago, initially implemented dial service with telephone numbers consisting of three letters and four digits (3L-4N) according to a system developed by W. G. Blauvelt of AT&T in 1917. [1]
A telephone prefix is the first set of digits after the country, and area codes of a telephone number. In the North American Numbering Plan countries (country code 1), it is the first three digits of a seven-digit local phone number, the second three digits of the 3-3-4 scheme. In other countries, both the prefix and the number may have ...
For example, 234 235-5678 is a valid telephone number; with area code 234, central office prefix (exchange) 235, and line number 5678. The number 234 911-5678 is invalid, because the central office code must not be in the form N11.
not in use; code is reserved for directory assistance applications 1-NPA-555-01XX is used for fictional telephone numbers; 1-NPA-555-1212 is used for directory assistance; and other 1-NPA-555-XXXX numbers can be used for other 555 services; 556: not in use; available for personal communications services: 557
Country codes are defined by the International Telecommunication Union (ITU) in ITU-T standards E.123 and E.164. The prefixes enable international direct dialing (IDD). Country codes constitute the international telephone numbering plan. They are used only when dialing a telephone number in a country or world region other than the caller's.
Mobile phones use geographic area codes. Exchanges may service on mobile devices; local numbers are portable between wired and wireless carriers. While area code 600 has been established as a non-geographic code that can be used by mobile phones, the only significant mobile usage has been for satellite phone service in remote regions. Cape ...