Area codes 819 and 873 are area codes for central and western Quebec, Canada, including the Quebec portion of the National Capital Region, and the entire Hudson Strait and Ungava Bay coastlines of Quebec. Major cities in the 819 territory include Gatineau, Sherbrooke and Trois-Rivières.
The incumbent local exchange carriers in 819/873 are Bell Canada, Bell Aliant, Telus, as well as Télébec and other independent companies. From 1992 to 1997, Northwestel was also an incumbent carrier in 819 as it included former Bell Canada points in the Northwest Territories.
Originally, Quebec was divided between two area codes. 514 originally covered the entire western half of Quebec from the US border to Hudson Strait, while 418 served the eastern half. In a 1957 flash cut, the 514 area was split into three segments - the southernmost (including Montreal) remained 514, the middle became 819, and the northern part, which had no telephone services, was added to 418. 819 thus bordered 613 and the new 705 codes in Ontario and 418 on the east and north, and the remainder of 514 on the south.
When telephone service was introduced in the eastern Northwest Territories (most of this is now the territory of Nunavut created in 1999), at Frobisher Bay in 1958, Bell Canada nominally made it part of Area code 418. Through the 1960s and 1970s, telephone service was introduced, by Bell Canada at other locations in the eastern Northwest Territories and in locations along the Quebec Arctic coastline, as well as by Sotel, an independent company, in the James Bay region. These non-diallable locations also became part of 418.