Area code 604


Area code 604 is a telephone area code that serves southwestern British Columbia, Canada: the Lower Mainland, Sunshine Coast, Howe Sound / Sea to Sky Corridor, Fraser Valley and the lower Fraser Canyon regions. It primarily serves the city of Vancouver and surrounding regions.

History

604 is one of the original 86 area codes assigned in 1947 in the contiguous United States and the then-nine provinces of Canada, and served the entire province of British Columbia. Until 1988, area code 604 also included Point Roberts, Washington, a pene-enclave of the United States; Point Roberts was transferred in 1988 to area code 206 and is now served by area code 360.
Despite British Columbia's growth in the second half of the 20th century, 604 remained the province's sole area code for nearly 50 years. By the mid-1990s, however, the need for a new area code in the province could no longer be staved off, largely due to Canada's number allocation system. Every competitive local exchange carrier in the country is allocated blocks of 10,000 numbers—corresponding to a single three-digit prefix—for every rate centre where it offers service, even for the smallest hamlets.
While smaller rate centres usually do not need that many numbers, once a number is assigned to a carrier and rate centre, it cannot be moved elsewhere, even to a larger rate centre. Additionally, some larger cities are split between multiple rate centres that have never been amalgamated. This resulted in thousands of wasted numbers, and the growing popularity of cell phones, pagers and fax machines only exacerbated this. The number shortage was particularly severe in the Lower Mainland, which was home to most of the province's landlines, as well as most of its other telecommunications devices requiring phone numbers.
In 1997, 604 was cut back to the Lower Mainland, with the new area code 250 created for the remainder of the province.
The 1997 split was intended as a long-term solution for the Lower Mainland. However, within three years, 604 was close to exhaustion once again due to the aforementioned number allocation problem and the continued proliferation of cell phones and pagers. While numbers tended to be used up fairly quickly in Vancouver and its immediate neighbours due to their rapid growth, the number allocation problem was still severe in the Lower Mainland as a whole.
On November 3, 2001, area code 778 was implemented as a concentrated overlay for the two largest regional districts in the Lower Mainland, Metro Vancouver and the Fraser Valley Regional District. This experiment was announced in NANP planning letter PL-246. While the remainder of the Lower Mainland continued to use only 604, the addition of area code 778 required the implementation of ten-digit dialling throughout the region.
The Canadian Radio-television and Telecommunications Commission announced on June 7, 2007, that 778 would become an overlay for the entire province on July 4, 2007, after the same number allocation problem that previously afflicted 604 brought 250 close to exhaustion. Effective June 23, 2008, ten-digit dialling became mandatory in British Columbia, and attempts to make a seven-digit call triggered an intercept message with a reminder of the new rule. After September 12, 2008, seven-digit dialling was no longer functional. Overlays have become the preferred method of relief in Canada, as they offer an easy workaround for the number allocation problem.
The incumbent local exchange carrier in 604 and 778 is Telus. Through "number portability" and sub-allocation of all numbers in some exchanges to a competitor, many numbers in the 778 area code are now serviced by Shaw Cablesystems.
On June 1, 2013, area code 236 was implemented as a distributed overlay of area codes 604, 250, and 778. It is expected to be exhausted in May 2020. As a result, area code 672 was implemented as an additional distributed overlay on May 4, 2019, to relieve area codes 604, 250, 778, and 236.

Communities included