Area codes 418, 581, and 367 are telephone area codes in the North American Numbering Plan (NANP) for the eastern portion of the Canadian province of Quebec. Area code 418 was originally assigned to the numbering plan area, but all three area codes now form an overlay plan for this territory. Cities in the numbering plan area include Quebec City, Saguenay, Lévis, Rimouski, Saint-Georges, Alma, Thetford Mines, Sept-Îles, Baie-Comeau and Rivière-du-Loup. Also served are the Gaspé Peninsula, Côte-Nord, southeastern Mauricie, and the tiny hamlet of Estcourt Station, in the U.S. state of Maine. History Ontario and Quebec were the only provinces that received assignments of multiple area codes by the American Telephone and Telegraph Company (AT&T) when the original North American area codes were created in 1947. The eastern part of Quebec received area code 418, while area code 514 was assigned for the western part. Nominally, northwestern Quebec, one of the few areas of North America without telephone service, was reassigned from area code 514 to area code 418 in 1957. From the 1950s to the 1970s, area code 418 was also the area code for the eastern Northwest Territories. However, in the 1970s, as direct distance dialling was introduced to the far northern and western portions of 418, those areas were reassigned to area code 819. Despite Quebec City's rapid growth, by the turn of the millennium, area code 418 was the last of Quebec and Ontario's original four area codes not to have been split. By 2006, however, area code 418 was on the brink of exhaustion because of Canada's system of number allocation. Every competitive local exchange carrier is allocated blocks of 10,000 numbers, which correspond to a single three-digit prefix, for every rate centre in which it plans to offer service, even for small hamlets. Once a number is assigned to a carrier and rate centre, it cannot be moved elsewhere even if a rate centre has more than enough numbers to serve it. That resulted in thousands of wasted numbers, a problem that was worsened by the proliferation of cellphones and pagers, especially in the larger cities. Additionally, a number of "megacities" created in 2002 are split between multiple rate centres, which have never been amalgamated. For example, Saguenay is split between four rate centres. In 2007, the CRTC assigned area code 581 as an overlay for 418. The implementation of area code 581