Area code 318 is a telephone area code in the North American Numbering Plan (NANP) for the northern and central parts of the U.S. state of Louisiana. The area code was assigned in 1957 in an area code split of area code 504, to a numbering plan area that comprised nearly all of the state west of the Mississippi River, stretching from the Gulf of Mexico north to the border with Arkansas. In 1999, the southern half of the original 318, including Lafayette and Lake Charles, received area code 337.
During the initial trials of direct distance dialing (DDD) in 1951, area code 318 was temporarily used as a destination code for San Francisco. Oakland and San Francisco had separate toll switches, so that calls had to be routed accordingly depending on the final destination. As the telephone equipment used at the time handled only three-digit translation, the temporary use of a distinct area code was required to distinguish between the two Bay Area cities. Area code 318 was used temporarily to specify San Francisco and areas north of the Golden Gate Bridge, while calls with destinations in Oakland or the East Bay used area code 415. When the electromechanical card-translator became available by 1953, translations using six digits were possible; the 318 code no longer was required. The entire San Francisco Bay Area returned to using area code 415.
In 1957, Louisiana's original area code 504 was split to create a numbering plan area with area code 318 for all of the state west of the Mississippi River, stretching from the Gulf of Mexico north to the border with Arkansas.
In 1999, the southern half, including Lafayette and Lake Charles, was split off with area code 337.
Further relief will be required by 2025, as 318 is expected to exhaust by early 2026. [1] The relief area code will be area code 457. [2] The relief date has not yet been determined. A transition to ten-digit dialing will be required before relief is implemented.
Direct distance dialing (DDD) is a telecommunication service feature in North America by which a caller may, without operator assistance, call any other user outside the local calling area. Direct dialing by subscribers typically requires extra digits to be dialed as prefixes to the directory telephone number of the destination. International Direct Distance Dialing (IDDD) extends the system beyond the geographic boundaries of the North American Numbering Plan (NANP).
The North American Numbering Plan (NANP) is a telephone numbering plan for twenty-five regions in twenty countries, primarily in North America and the Caribbean. This group is historically known as World Zone 1 and has the telephone country code 1. Some North American countries, most notably Mexico, do not participate in the NANP.
Area codes 415 and 628 are telephone area codes in the North American Numbering Plan (NANP) for the city of San Francisco and its northern suburbs in Marin County, and the northeast corner of San Mateo County in the U.S. state of California. Area code 415 was one of the eighty-six original North American area codes established in 1947, but modified in geographic configuration later. Area code 628 was assigned in 2015 to form an overlay in that numbering plan area in mitigation of central office prefix exhaustion.
Area codes 954 and 754 are the telephone area codes in the North American Numbering Plan (NANP) for Broward County, Florida. Notable cities in the numbering plan area are Fort Lauderdale, Plantation, Hollywood, Parkland, Sunrise, Pompano Beach, Coral Springs, Deerfield Beach, Davie, Weston, Dania Beach, Oakland Park and Pembroke Pines.
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.
Seven-digit dialing is a telephone dialing procedure customary in some territories of the North American Numbering Plan (NANP) for dialing telephone numbers in the same numbering plan area (NPA). NANP telephone numbers consist of ten digits, of which the leading three are the area code. In seven-digit dialing it is not necessary to dial the area code. The procedure is also sometimes known as local format or network format.
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 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 code 559 is a telephone area code in the North American Numbering Plan for the central San Joaquin Valley in central California. The numbering plan area includes the counties of Fresno, Madera, Kings, and Tulare, an area largely coextensive with the Fresno and Visalia-Porterville metropolitan areas. The area code was placed in service in 1998, when its services area was split from that of area code 209.
Area codes 608 and 353 are telephone area codes in the North American Numbering Plan for much of southwestern Wisconsin, including the state capital city Madison. Area code 608 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, 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 activatlon is contingent on complete exhaustion of central office codes for 608.
Area code 250 is a telephone area code in the North American Numbering Plan (NANP) for the Canadian province of British Columbia outside the Lower Mainland, including Vancouver Island–home to the provincial capital, Victoria–and the province's Interior region. In addition, the numbering plan area extends into the United States community of Hyder, Alaska, located along the Canada–United States border near the town of Stewart. The incumbent local exchange carriers that service the area code are Telus, Northwestel, and CityWest in the city of Prince Rupert.
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 codes 408 and 669 are telephone area codes in the North American Numbering Plan (NANP) in the U.S. state of California. The numbering plan area comprises most of Santa Clara County and Northern Santa Cruz County, and includes Gilroy, Morgan Hill, Saratoga, Los Gatos, Monte Sereno, Milpitas, Sunnyvale, Santa Clara, Cupertino, Campbell, and San Jose.
Area codes 510 and 341 are telephone area codes in the North American Numbering Plan (NANP) serving much of the East Bay in the U.S. state of California. They cover parts of Contra Costa County and western Alameda County, including the city of Oakland, but excluding Dublin, Livermore, Pleasanton, and Sunol.
Area codes 707 and 369 are telephone area codes in the North American Numbering Plan (NANP) for the northwestern part of the U.S. state of California. The area codes serve part of the northern San Francisco Bay Area, as well as the North Coast. Major cities in the area codes include Napa, Sebastopol, Vallejo, Benicia, Fairfield, Santa Rosa, Windsor, Healdsburg, Rohnert Park, Petaluma, Fort Bragg, Rio Vista, Crescent City, Eureka, Clearlake, Vacaville, Dixon, and Ukiah. 707 was created by a split of area code 415 on March 1, 1959. Area code 369 was added to the numbering plan area (NPA) on February 1, 2023, to form an overlay numbering plan in the service area.
Area codes 301, 240, and 227 are telephone area codes in the North American Numbering Plan (NANP) for the western part of the U.S. state of Maryland. The numbering plan area (NPA) comprises Maryland's portion of the Greater Washington, D.C. metro area, portions of southern Maryland, along with rural western Maryland. This includes the communities of Cumberland, Frederick, Hagerstown, Gaithersburg, Potomac, Germantown, Bethesda, Rockville, Landover, Silver Spring, and Waldorf.
Area codes 609 and 640 are telephone overlay area codes in the North American Numbering Plan (NANP) for the central and southern parts of the U.S. state of New Jersey. The numbering plan area includes the cities of Trenton, Princeton, Ewing, Hamilton, and southeastern parts of the state and the Jersey Shore, including Atlantic City and Long Beach Island. In terms of geographic coverage, it is the largest numbering plan area in New Jersey. Area code 609 was created in a split of area code 201 in c. 1956. Area code 640 is an additional area code for the area, created on September 17, 2018.
Area code 810 is a telephone area code in the North American Numbering Plan for the east-central part in the U.S. state of Michigan. The numbering plan area (NPA) comprises the cities of Flint, Lapeer, Port Huron, and the southern portion of the Thumb.
Area codes 270 and 364 are telephone overlay area codes in the North American Numbering Plan (NANP) for the Commonwealth of Kentucky's western and south central counties. Area code 270 was assigned in a split of numbering plan area 502 in 1999. Area code 364 was added to the same numbering plan area in 2014, after having been first considered for 270-relief planning in 2007. Major cities in the numbering plan area include Hopkinsville, Paducah, Henderson, Murray, Bowling Green, Owensboro, Elizabethtown, and Madisonville. It also includes Kentucky's share of Fort Campbell.
The expansion of the North American Numbering Plan (NANP) is the anticipated requirement for providing more telephone numbers to accommodate future needs beyond the pool of ten-digit telephone numbers. Ten-digit telephone numbers have been in use in the United States and Canada in long-distance telephone service since the 1950s. An October 2020 analysis estimated that the numbering plan would not be exhausted until after the year 2050.
| North: 870 | ||
| West: 409, 430/903, 936 | 318 | East: 601/769, 662 |
| South: 225, 337 | ||
| Arkansas area codes: 479, 501, 870 | ||
| Mississippi area codes: 228, 601/769, 662 | ||
| Texas area codes: 210/726, 214/469/972, 254, 281/346/713/832, 325, 361, 409, 430/903, 432, 512/737, 682/817, 806, 830, 915, 936, 940, 956, 979 | ||