Area codes 519, 226, 548, and 382 are overlay telephone area codes in the North American Numbering Plan (NANP) for most of southwestern Ontario.
In telecommunications, an area code overlay complex is a telephone numbering plan that assigns multiple area codes to a geographic numbering plan area (NPA). Area code overlays are implemented in territories of the North American Numbering Plan (NANP) to mitigate exhaustion of central office codes in growth areas. The method has been in use since 1992, and has been the preferred and exclusive method of relief since 2007.
Ten-digit dialing is a telephone dialing procedure in the countries and territories that are members of the North American Numbering Plan (NANP). It is the practice of including the area code of a telephone number when dialing to initiate a telephone call. When necessary, the ten-digit number may be prefixed with the trunk code 1, which is referred to as 1+10-digit dialing or national format.
Area code 867 is the area code in the North American Numbering Plan (NANP) for the three Canadian territories, all of which are in Northern Canada. The area code was created on October 21, 1997, by combining regions that were previously served with area code 403 and area code 819 in one numbering plan area (NPA). As the least populated NPA in mainland North America, serving about 100,000 people, it is geographically the largest, at 3,921,739 km2 (1,514,192 sq mi), with Alaska (907) a distant second.
Area codes 920 and 274 are telephone area codes in the North American Numbering Plan (NANP) for a large area of eastern Wisconsin. Area code 920 was created on July 26, 1997, in a split of area code 414, one of the original North American area codes of 1947. 274 was added to the same numbering plan area (NPA) on May 5, 2023 to create an area code overlay.
Area codes 514, 438, and 263 are telephone area codes of the North American Numbering Plan (NANP) for Montreal and most of its on-island suburbs, specifically the Island of Montreal and Île Perrot in the Canadian province of Quebec.
Area code 608 is a telephone area code in the North American Numbering Plan for much of southwestern Wisconsin, including the state capital city Madison. The area code was assigned in 1955 to a numbering plan area created from areas with area code 414 and area code 715, and was the third area code created in Wisconsin. Rapid growth of the area, specifically in Dane County, has brought the area code close to exhaustion of central office prefixes, with NANPA projections in 2022 projecting the need for relief by late 2023. In September 2022, the Wisconsin Public Service Commission and North American Numbering Plan Administrator (NANPA) announced an overlay complex for the numbering plan area with new area code 353, with an in-service date of September 15, 2023. New central office code orders were accepted starting on July 11, 2023, but can only be activated once all 608 central office codes are assigned.
Area codes 813 and 656 are area codes in the North American Numbering Plan for the U.S. state of Florida in the city of Tampa, Florida, and its surrounding areas, such as Zephyrhills and Oldsmar. In 2022, due to exhaustion of central office prefixes, area code 656 was added to the service area forming an overlay complex.
Area codes 876 and 658 are telephone area codes in the North American Numbering Plan (NANP) for Jamaica.
Area codes 204, 431, and 584 are telephone area codes in the North American Numbering Plan (NANP) for the Canadian province of Manitoba. Area code 204 is one of the nine original North American area codes assigned to Canada in 1947. Area codes 431 and 584 were assigned to the same numbering plan area (NPA) in 2012 and 2022, respectively, forming an overlay complex.
Area codes 778, 236, and 672 are telephone area codes in the North American Numbering Plan (NANP) for the Canadian province of British Columbia. They form an overlay complex with area code 604, which serves only a small southwestern section, the Lower Mainland, of the province, and area code 250, which serves the rest of the province.
Area codes 306, 639, and 474 are telephone area codes in the North American Numbering Plan (NANP) for the entire Canadian province of Saskatchewan. Area code 306 is the original area code, and area codes 639 and 474 were added to create an overlay complex for the entire province. The incumbent local exchange carrier is SaskTel.
Area code 403 is a telephone area code in the North American Numbering Plan (NANP) for the Canadian province of Alberta. The numbering plan area encompasses the southern third of the province, which includes the Calgary area. This numbering plan area is also served by area codes 587, 825, and 368, which form a complex overlay for all of Alberta.
Area codes 506 and 428 are the telephone area codes in the North American Numbering Plan (NANP) for the Canadian province of New Brunswick. Area code 506 was created in 1955 in a split of numbering plan area (NPA) 902. Area code 428 was added to the same numbering plan area in 2023 to form an overlay plan of the area.
Area code 604 is a telephone area code in the North American Numbering Plan for southwestern British Columbia, Canada. The numbering plan area comprises the Lower Mainland, Sunshine Coast, Howe Sound / Sea to Sky Corridor, Fraser Valley and the lower Fraser Canyon regions. The major city is Vancouver. The area code is one of the nine original North American area codes assigned to Canada in 1947.
Area codes 587, 825, and 368 are telephone area codes in the North American Numbering Plan (NANP) for the entire Canadian province of Alberta. They form an overlay with area code 403 of southern Alberta, and northern Alberta's 780. The complex overlay involving a total of five area codes in Alberta mandated ten-digit dialing throughout the province.
