NPA NXX data is a numbering plan that is in use in North America to provide current telephone area code prefix and exchange numbering assignments and associated carrier data. This data is suitable for applications such as call routing and caller ID systems, among others.
The North American numbering plan governs telephone numbers for the Public Switched Telephone Networks in North America. The NPA NXX data format represents the area code, Central Office within the NPA and station within the NXX. NPA NXX data products use is mainly in call routing, CDR processing and analysis, jurisdictional traffic analysis, TCPA, caller id systems and telephone exchange validation among other uses.
The NPA NXX data use is over North America in countries such as Canada, US, Jamaica, Trinidad and Tobago, and Grenada, among others. Its databases keep updating monthly to provide current information on telephone codes prefixes and associated carrier data. In areas where the NPA does not require an overlay, numbers of the form NXX-XXXX are local and do not have toll charges, unlike numbers of the form 1-NPA-NXX-XXXX are long distance and they associate carrier charges. The prefixed 1 is a method of toll alerting when an international call is placed.
The user data obtained from the NPA NXX data is only in use when routing, rating, billing of calls or performing network maintenance checks. Number Portability Administration Center, or NPAC, users provide the user data and the NPA NXX has restrictions that apply on how to use the data.