Information About Postal Codes and Zip Codes
Area code 905 (with overlay area codes 289 and 365) is a telephone dialling area in southern Ontario, Canada. It includes the Niagara Peninsula, Hamilton, Oshawa, and the suburban greater Toronto area. It was assigned on 4 October 1993, as a split from area code 416. 289 began sharing the service area on 9 June 2001, since then, all local calls require ten-digit dialling. On 13 April 2010, the Canadian Radio-television and Telecommunications Commission (CRTC) announced that area codes 905 and 289 would be overlaid by a third area code, 365, in early 2013.
It surrounds area code 416/647/437 (the city of Toronto) and is bounded with area code 519/226 in the west, 705/249 in the north, 613/343 in the east, and area code 716 on the eastern prong of the Niagara Peninsula.
The incumbent local exchange carrier for these area codes is Bell Canada, which acquired the remaining independent company around 1980.