Area Code Atlas

Teletypewriter services reassigned from area code 610 to 600

Teletypewriter services previously provisioned with area code 610 were reassigned to area code 600 in 1993, returning 610 to the pool of unassigned area codes for general purposes. This change centralized specialized non-geographic services under the new 600 code.

INTRODUCTION OF SERVICE ACCESS CODE (SAC) 600 IN CANADA

Introduction of area code 600 in Canada for non-geographic services

Area code 600 was introduced on April 15, 1993, as a non-geographic code for specialized telecommunication services in Canada. The code was established to support applications such as telex, ISDN, and mobile satellite communications, particularly in remote regions where conventional infrastructure was unavailable, replacing the previous use of area code 610 for teletypewriter services.

NPA 610 retired for Canadian TWX, replaced by 600

The Canadian use of area code 610 for TWX service was terminated on October 31, 1993, replaced by area code 600 for non-geographic applications.

CRTC issues guidelines for area code 600

The Canadian Radio-television and Telecommunications Commission issued guidelines for the assignment of central office prefixes within area code 600 on June 30, 2006. These guidelines established the framework for allocating numbers to carriers and defined the scope of non-geographic services eligible for assignment.

Canadian Numbering Plan and Dialling Plan version 5.0 published

Version 5.0 of the Canadian Numbering Plan and Dialling Plan was published on October 26, 2011, documenting the structure and administration of area codes in Canada, including the status of non-geographic codes such as 600 and its reserved relief codes (622, 633, 644, 655, 677, and 688).