Area code 604

Telephone area code 604 serves southwestern British Columbia: 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. 604 is one of the original 86 area codes assigned in 1947 in the contiguous United States and the then-nine provinces of Canada. It originally served the entire province until a geographic split was implemented in 1997, creating the new area code 250 for the remainder of the province.

Until 1988, area code 604 also included Point Roberts, Washington, a pene-enclave of the United States; Point Roberts was transferred in 1988 to 206 and is now served by area code 360.

While the 1997 split was intended as a long-term solution, 604 was close to exhaustion within three years due to Canada's inefficient number allocation system. Every competitive local exchange carrier in the country is allocated blocks of 10,000 numbers for every rate centre where it offers service, even for the smallest hamlets. Once a number is assigned to a carrier and rate centre, it cannot be moved elsewhere, even when it is in an area that does not need nearly as many numbers as a larger one. This has resulted in many wasted numbers. The problem was exacerbated in the Lower Mainland (and particularly the Vancouver area) because it is home to most of the province's landlines, as well as most of its cell phones.

On November 3, 2001, area code 778 was implemented as a concentrated overlay for Metro Vancouver and the Fraser Valley Regional District. This experiment was announced in NANP planning letter PL-246. The remainder of the Lower Mainland continued to use only 604. The addition of area code 778 required the implementation of ten-digit dialing throughout all of southwestern British Columbia.

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