456 NXX Codes

The purpose of NPA 456 and its associated NXXs is to enable the routing of inbound international calls for carrier-specific services, particular to a service providers network, to and between NANP Area countries. This is accomplished by providing carrier identification within the dialed digits of the E.164 number. More specifically, the prefix following 456 (456-NXX) identifies the carrier. Use of these numbers enables the proper routing of inbound international calls destined for these services.

456-NXX codes are assigned according to the Industry Numbering Committee (INC) International Inbound NPA Assignment Guidelines, as accepted or modified by the Canadian Steering Committee on Numbering. If you wish to apply for an assignment, fill out the application form included in the assignment guidelines, and return it to the Canadian Numbering Administrator.

Current 456-NXX assignments are shown below:

The current approved Canadian Adjunct to the INC International Inbound NPA (INT/NPA/NXX) Assignment Guidelines are available below.  Some of these are accessed directly from the CRTC web resources:

• International Inbound NPA (INT/NPA/NXX) Assignment Guidelines
• Appendix A - Audit Process and Forms

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