NXX definition (Phone Scoop)
...NXX is most commonly used to refer to three-digit code that forms the second part of a 10-digit North American phone number (digits 4-6). This is also known as the "central office code" or "exchange"....
https://www.phonescoop.com/glossary/term.php?gid=301
NPA NXX Area Code Database List Directory with Exchanges
...NPA NXX Area Code Database List & demographics, Directory of Area Codes NPA NXX, Exchanges, CLLi, Lat/Lon, Carrier, Landline/Cell indicator....
https://www.area-codes.com/
Local calling guide: NPA-NXX search
...Local calling guide Effective date within past or next days Effective date searches are available only for US area codes. Our sources for non-US NPA-NXX data do not provide this information. If you want to search an entire area code regardless of activity, leave both the next and past days fields set to zero....
https://www.localcallingguide.com/lca_prefix.php
CO Codes/Thousands-Blocks | NANPA
...CO Codes/Thousands-BlocksA Central Office (CO) code or NXX refers to the second three digits (also called digits D-E-F) of a ten-digit telephone number in the form of NPA-NXX-XXXX, where N represents any one of the numbers 2 through 9 and X represents any one of the numbers 0 through 9. CO codes are also known as an exchange, or prefix, or an NXX.A thousands-block refers a range of one ......
https://www.nanpa.com/numbering/co-codesthousands-blocks
North American Telephone Exchange Lookup by NPA NXX
...North American NPA NXX Lookup Central Office Details From NPA NXX This lookup uses the North American NPA NXX Wire Center Edition Database and supplemental data to find the Wire Center, Rate Center, locality, LATA, carrier, and other details associated with any United States or Canadian NPA NXX combination....
https://www.npanxxsource.com/nalennd.php
What do the terms NPA and NXX mean? | Bandwidth Help Center
...What is NXX? NXX, also known as the Central Office Code or Exchange, is a three-digit code that forms the second part of a 10-digit phone number. For example: In the phone number 555-101-1234, the NXX is 101....
https://www.bandwidth.com/support/en/articles/12823323-what-do-the-terms-npa-and-nxx-mean
Understanding NXX Prefixes: Integral Components of North American ...
...Understanding NXX Prefixes: Integral Components of North American Telephone Numbers NXX prefixes are a fundamental aspect of the North American Numbering Plan (NANP), which is used throughout the United States, Canada, and parts of the Caribbean....
https://solveforce.com/understanding-nxx-prefixes-integral-components-of-north-american-telephone-numbers/
NXX in the North American Numbering Plan - 123NET
...NXX codes remain critical in today?s phone systems, especially for call routing and network management. Despite advancements in technology, the basic structure of the NXX within the North American Numbering Plan continues to serve as a geographical identifier in landlines....
https://www.123.net/blog/in-depth-look-at-nxx-in-the-north-american-numbering-plan/
NPA NXX Area Code and Prefix Lookup by Geographic Location
...Find all NPA NXX used in a geographic area. This lookup uses the NALENND ® North American Local Exchange NPA NXX Database? - Rate Center Edition to find the telephone exchange Rate Centers, area codes (NPA), and prefixes (NXX) used in the area surrounding any United States, Canadian, or Caribbean location....
https://www.quentinsagerconsulting.com/area-code-lookup.html
NXX - NENA Knowledge Base
...NXX is most commonly used to refer to three-digit code that forms the second part of a 10-digit North American phone number (digits 4-6). This is also known as the "central office code" or "exchange." Traditionally, in the age of competing phone companies, each NXX is assigned to one company....
https://kb.nena.org/wiki/NXX