Area codes 314 and 557 are telephone area codes in the North American Numbering Plan (NANP) in the U.S. state of Missouri, serving the city of St. Louis and most of its inner-ring suburbs in neighboring St. Louis County. The numbering plan area is bordered to the west by area code 636, which serves St. Louis' outer suburbs to the west, south, and north. Across the Mississippi River to the east, 314 is adjacent to area code 618, which serves southern Illinois and most of Metro East. Area code 557 was added to the 314 numbering plan area on August 12, 2022, to form an overlay numbering plan.
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 614 and 380 are telephone area codes in the North American Numbering Plan (NANP) for all or part of four counties in central Ohio, surrounding and including the state capital of Columbus. Area code 614 is one of the original area codes assigned for Ohio in 1947, while area code 380 is an overlay code covering the same territory.
Area codes 740 and 220 are telephone area codes in the North American Numbering Plan (NANP) for the southeastern and central parts of Ohio. The numbering plan area (NPA) includes the cities of Athens, Belpre, Cadiz, Chillicothe, Circleville, Coshocton, Delaware, Gallipolis, Heath, Ironton, Jackson, Lancaster, Laurelville, Logan, Marietta, Marion, Mount Vernon, Nelsonville, Newark, Newcomerstown, Pataskala, Portsmouth, Rockbridge, Steubenville, Washington Court House, and Zanesville, Shadyside and the surrounding areas. It does not include the city of Columbus and rate centers in Franklin County which primarily use area code 614. Although it is Ohio's largest area code by geographic size, Southeastern Ohio is largely rural and has fewer residents overall than the rest of the state except in the areas near Columbus.
Area codes 909 and 840 are telephone area codes in the North American Numbering Plan for the far-eastern part of Los Angeles County and southwestern San Bernardino County in the U.S. state of California. Area code 909 was created on November 14, 1992 in an area code split of 714, and 840 was added to the numbering plan area to form an overlay complex effective February 23, 2021.
Area codes 202 and 771 are telephone area codes in the North American Numbering Plan (NANP) for Washington, D.C.
Area codes 812 and 930 are telephone area codes in the North American Numbering Plan (NANP) for the southern third of the state of Indiana.
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 one of the original North American area codes assigned in 1947. Area codes 639 and 474 were added to the numbering plan area in creation of an overlay complex for the entire province in 2013 and 2021, respectively. 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 code 780 is a telephone area code in the North American Numbering Plan (NANP) for the Canadian province of Alberta. The numbering plan area comprises the northern two thirds of the province, including the Edmonton area. The area code was established in 1999 in a split of area code 403, which had served the entire province since the establishment of the original North American area codes in 1947. The numbering plan area is also served by area codes 587, 825, and 368, which form a complex overlay for all of Alberta.
Area codes 678, 470, and 943 are telephone area codes in the North American Numbering Plan (NANP) for the U.S. State of Georgia in the Atlanta metropolitan area. The area codes are assigned in an overlay plan to a combined numbering plan area (NPA) consisting of 404 and 770.
Area codes 304 and 681 are telephone area codes in the North American Numbering Plan (NANP) for the entirety of the U.S. state of West Virginia. The numbering plan area was established in October 1947 with area code 304, as one of the eighty-six original North American area codes. Area code 681 was added to the same area in an overlay plan that took effect on March 28, 2009.
Area code 412 is a telephone area code in the North American Numbering Plan (NANP) for the Commonwealth of Pennsylvania. The numbering plan area (NPA) comprises the city of Pittsburgh, most of surrounding Allegheny County, and small portions of Washington and Westmoreland counties. The area code was one of the original North American area codes created in 1947, when it was assigned to the entire southwestern corner of the state. On August 17, 2001, the numbering plan area was converted to an overlay complex with area code 878, which also forms an overlay with area code 724, in the surroundings of the 412 service area.
Area codes 419 and 567 are telephone area codes in the North American Numbering Plan (NANP) for the northwestern part of the U.S. state of Ohio. The largest city served by these area codes is Toledo.
Area codes 317 and 463 are telephone area codes in the North American Numbering Plan (NANP) for Indianapolis and nine surrounding counties in central Indiana. The numbering plan area (NPA) comprises all or parts of Marion, Boone, Hancock, Hamilton, Hendricks, Johnson, Madison, Morgan, and Shelby counties. 317 is the original area code of the NPA, created in 1947, while 463 is an overlay code for the same area that was added in 2016, making ten-digit dialing mandatory for all calls in the region.
Area codes 513 and 283 are telephone area codes in the North American Numbering Plan (NANP) for the southwest of the U.S. state of Ohio, including Cincinnati and surrounding cities, such as Forest Park, Hamilton, Lebanon, West Chester, Mason, Maineville, Middletown, Milford, Norwood, Oxford, Harrison, Cleves, Miamitown and Trenton.
Area codes 816 and 975 are telephone area codes in the North American Numbering Plan (NANP) for most of the Missouri side of the Kansas City metropolitan area, the St. Joseph area, and all or part of 15 surrounding counties in northwestern Missouri. The numbering plan area originally comprised most of the northern and western two-thirds of the state, bordering with Arkansas, Illinois, Iowa, Kansas, Nebraska, and Oklahoma, but has been reduced to a ribbon bordering Kansas. 816 is one of the original 86 area codes created in 1947. The numbering plan area was converted to an overlay complex with area code 975 in 2023.
Area code 870 is a telephone area code in the North American Numbering Plan (NANP) for southern, eastern, and most of northern Arkansas. It was created on April 14, 1997 in a split from area code 501, Arkansas's original area code of 1947.
Area codes 937 and 326 are telephone area codes in the North American Numbering Plan (NANP) assigned to a numbering plan area (NPA) that encompasses much of the southwestern part of the U.S. state of Ohio, including Dayton and Springfield. Area code 937 was established in September 1996, in a split of area code 513. Area code 326 was added to the numbering plan area to form an overlay complex in March 2020.
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.
