Published: May 12, 2023
For 50 years served by area code 604 alone, the Canadian province of British Columbia is about to become the geographical area in the North American Numbering Plan using the most area codes for a single overlay complex. This is a side effect of an old phone number allocation system still used in Canada and which provides carriers with blocks of 10,000 phone numbers corresponding to each single central office code in all served rate centers. Although smaller rate centers do not use this many phone numbers, once allocated to a carrier and rate center a number can not be moved.
Currently served by overlay complexes 604/778/236/672 and 250/778/236/672, covering the Vancouver area and the rest of the province respectively, a new area code 257 was announced for British Columbia on May 10, 2023. This new Numbering Plan Area Code is scheduled to enter service on May 24, 2025 and, just like the other BC area codes except for 250 and 604, the new 257 area code will serve the entire province. So starting May 24, 2025 we'll have these overlay complexes: 604/778/236/672/257 and 250/778/236/672/257.
See official NANPA announcement and rate center list (PDF document).