Area codes 240 and 301

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Area code 215Area code 856Area code 484Area code 717Area code 814Area code 724Area code 202Area code 571Area code 757Area code 302Area codes 410, 443, and 667Area code 304/681Area code 804Area code 434Area code 540Area codes 240 and 301
Maryland consists of the red and blue areas. The red area indicates area codes 240 and 301. This map is clickable; click on any neighboring area code to go to the page for that code.

North American area codes 240 and 301 are telephone area codes for the western half of Maryland. They serve Maryland's portion of the Greater Washington, D.C., metro area, portions of southern Maryland, and the more rural areas in the western portion of the state. This includes the communities of Cumberland, Frederick, Hagerstown, Gaithersburg, Rockville, Landover and Silver Spring.

North America Continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere

North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere; it is also considered by some to be a northern subcontinent of the Americas. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the west and south by the Pacific Ocean, and to the southeast by South America and the Caribbean Sea.

Telephone telecommunications device

A telephone, or phone, is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be heard directly. A telephone converts sound, typically and most efficiently the human voice, into electronic signals that are transmitted via cables and other communication channels to another telephone which reproduces the sound to the receiving user.

Maryland State of the United States of America

Maryland is a state in the Mid-Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east. The state's largest city is Baltimore, and its capital is Annapolis. Among its occasional nicknames are Old Line State, the Free State, and the Chesapeake Bay State. It is named after the English queen Henrietta Maria, known in England as Queen Mary.

Contents

History

The main area code, 301, was one of the original area codes established in 1947, and originally covered the entire state of Maryland. This was despite the fact that, then as now, the bulk of the state's population is split between two very large metropolitan areas–Baltimore and the Washington suburbs. From 1947 to 1990, it was possible for telephone users on the Maryland side of the Washington metropolitan area to dial any number in the region with only seven digits. Although the metro area was split between three area codes–the district's 202, Northern Virginia's 703, and Maryland's 301–it was a single local calling area. Every number on the Maryland and Virginia sides of the metro was given a "hidden" number in the District's 202, essentially using 202 for the entire metro. One consequence of this was that no central office codes could be duplicated in the D.C. area. For instance, if 202-574 was in use in the District or 703-574 was being used in Northern Virginia, the corresponding 301-574 exchange in Maryland could only be used in areas at a safe distance from the Washington metro area, such as the Eastern Shore.

Baltimore Largest city in Maryland

Baltimore is an independent city in the state of Maryland within the United States. Baltimore was established by the Constitution of Maryland as an independent city in 1729. With a population of 611,648 in 2017, Baltimore is the largest such independent city in the United States. As of 2017, the population of the Baltimore metropolitan area was estimated to be just under 2.808 million, making it the 20th largest metropolitan area in the country. Baltimore is located about 40 miles (60 km) northeast of Washington, D.C., making it a principal city in the Washington-Baltimore combined statistical area (CSA), the fourth-largest CSA in the nation, with a calculated 2017 population of 9,764,315.

Area code 202

Area code 202 is the North American telephone area code for Washington, D.C.. The area code was one of the original area codes established in October 1947 by AT&T in the North American Numbering Plan (NANP).

Northern Virginia

Northern Virginia, locally referred to as NOVA or NoVA, comprises several counties and independent cities in the Commonwealth of Virginia in the United States. It is a widespread region radiating westward from Washington, D.C. With 2.8 million residents, it is the most populous region of Virginia and the Washington metropolitan area.

By the end of the 1980s, the Washington metropolitan area was running out of prefixes. In order to free more available numbers, the suburban use of 202 was ended on October 1, 1990. As of that date, local calls from Maryland to either the District of Columbia or Virginia were required to include the area code when dialing. Local calls to Maryland from either the District of Columbia or Virginia also needed to include the area code while dialing. Local calls within Maryland did not require dialing the area code. [1]

Washington metropolitan area Metropolitan area in the United States

The Washington metropolitan area is the metropolitan area centered on Washington, D.C., the capital of the United States. The area includes all of the federal district and parts of the U.S. states of Maryland and Virginia, along with a small portion of West Virginia. While not a part of the Washington metropolitan area, St. Mary's County is part of the Baltimore–Washington metropolitan area.

Despite the presence of the Baltimore–Washington metropolitan area, 301 remained the exclusive area code for Maryland for 44 years, making Maryland one of the largest states with a single area code. By the end of the 1980s, it was apparent that breaking seven-digit dialing in the Washington area would not free up enough numbers to stave off the immediate need for a new area code. The number shortage was magnified by the fact that most of the Washington metro is a single LATA, meaning that many numbers in the District and Northern Virginia were unavailable for use.

Baltimore–Washington metropolitan area CSA in the United States

The Baltimore–Washington metropolitan area is a combined statistical area consisting of the overlapping labor market region of the cities of Washington, D.C. and Baltimore, Maryland. The region includes Central Maryland, Northern Virginia, three counties in the Eastern Panhandle of West Virginia, and one county in South Central Pennsylvania. It is the most educated, highest-income, and fourth largest combined statistical area in the United States.

Local access and transport area

Local access and transport area (LATA) is a term used in U.S. telecommunications regulation. It represents a geographical area of the United States under the terms of the Modification of Final Judgment (MFJ) entered by the United States District Court for the District of Columbia in Civil Action number 82-0192 or any other geographic area designated as a LATA in the National Exchange Carrier Association, Inc. Tariff FCC No. 4. that precipitated the breakup of the original AT&T into the "Baby Bells" or created since that time for wireline regulation.

Baltimore and the Eastern Shore were split off as area code 410 on October 6, 1991. The split largely followed metro area lines. However, part of Howard County, which is reckoned as part of the Baltimore area, stayed in 301 while the rest shifted to 410. [2] Normally, when an area code is split, the largest city in the old numbering plan area retains the existing area code—in this case, Baltimore. However, it was decided to let the Washington suburbs keep 301. Not only do the Washington suburbs have the bulk of the state's population,but Bell Atlantic (now Verizon) wanted to spare the large number of federal agencies on the Maryland side of the metro the expense and burden of having to change their numbers.

Eastern Shore of Maryland region of the state of Maryland, United States of America

The Eastern Shore of Maryland is a part of the U.S. state of Maryland that lies predominantly on the east side of the Chesapeake Bay and consists of nine counties. As of the 2010 census, its population was 449,226, with just under 8 percent of Marylanders living in the region. The term "Eastern Shore" distinguishes a territorial part of the State of Maryland from the Western Shore of Maryland, land west of the Chesapeake Bay.

Howard County, Maryland County in the United States

Howard County is a county in the central part of the U.S. state of Maryland. As of the 2010 census, the population was 287,085. Its county seat is Ellicott City.

This was intended as a long-term solution, but within four years 301 was close to exhaustion due to the proliferation of cell phones and pagers, especially in the Washington suburbs. To solve this problem, area code 240 was introduced on June 1, 1997, as the state's first overlay area code. [3] Overlays were a new concept at the time, and met with some resistance due to the requirement for ten-digit dialing. For this reason, conventional wisdom would have suggested a split in which the Washington suburbs would have kept 301 while Frederick and points west would have shifted to 240. However, Bell Atlantic wanted to spare residents, particularly in the more rural western portion, the burden of having to change their numbers.

In telecommunications, an overlay plan is a telephone numbering plan that assigns multiple area codes to a geographic numbering plan area (NPA). Overlaying area codes is practiced in the territories belonging to the North American Numbering Plan (NANP).

In the United States and Canada, ten-digit dialing is the practice of including the area code of a telephone number when dialing to initiate a telephone call. When necessary, a ten-digit number may be prefixed with the trunk code 1, which is often referred to as 11-digit dialing or national format.

Area code 227 is scheduled to be overlaid on 301/240 some time in the longer term to provide additional assignable numbers, although the current area codes are not expected to exhaust before 2024.

Geography

Counties served by these area codes include:

Local calls require 10-digit dialing (area code + number, leading "1" is not required).

Notes

  1. 1 2 3 4 Four counties were split between area code 301 and 410.
    • Anne Arundel County was assigned area code 410, except Laurel exchanges 210, 317, 490, 497, 498, 596, 604, 725, and 778 and Marlboro exchange 952 remained area code 301.
    • Carroll County was assigned area code 410, except Mount Airy exchange 829 remained area code 301.
    • Howard County was assigned area code 410, except Mount Airy exchange 829 and Laurel exchanges 210, 317, 490, 497, 598, 604, 725, and 776 remained area code 301.
    • Frederick County remained area code 301, except Union Bridge exchange 775 and New Windsor exchange 635 was assigned 410. [4]

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Area codes 201 and 551 area codes in the United States

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Area code 404 of the North American Numbering Plan (NANP) identifies a numbering plan area (NPA) that covers Atlanta, Georgia and its closest suburbs, roughly the area encircled by Interstate 285. It is an enclave area code, completely surrounded by area code 770, which serves most of Atlanta's suburbs. Both 404 and 770 are overlaid by area codes 678 and 470.

Area codes 706 and 762

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Area codes 615 and 629 are area codes in Tennessee serving Nashville and the 12 surrounding counties. 615 is the main area code, while 629 is an overlay covering the same area that began service in 2014. Murfreesboro, Franklin, Brentwood, Gallatin, Hendersonville, and Lebanon are other major cities in the 615/629 service territory.

Area codes 717 and 223

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Area codes 304 and 681 area codes of West Virginia

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Area codes 610 and 484

Area codes 610 and 484 are telephone area codes which serve the eastern and southeastern regions of Pennsylvania. The area includes areas to the west of Philadelphia, along with the cities of Allentown, Bethlehem, and Reading. It includes much of the Delaware Valley, including almost all of Delaware County and most of the Philadelphia Main Line.

Area codes 410, 443, and 667

Area codes 410, 443, and 667 are telephone area codes serving the eastern half of the U.S. state of Maryland, including the Baltimore metropolitan area and the Eastern Shore. The 410 area code is the main area code, while the 443 and 667 codes are overlay codes. 443 and 667 were primarily used with cell phones and CLEC carriers such as Comcast or Cavalier Telephone when introduced but have since become universal in their carrier availability.

Area codes 703 and 571

Area codes 703 and 571 are the North American Numbering Plan telephone area codes for northern Virginia, including the independent cities of Alexandria, Fairfax, Falls Church, Manassas, and Manassas Park, as well as all of Arlington and Fairfax counties and parts of Fauquier, Loudoun, Prince William, and Stafford counties. The main area code, 703, was created as one of the original 86 North American area codes in October 1947, and originally served the entire Commonwealth of Virginia. Area code 571 was created on March 1, 2000 as an overlay to 703.

Telephone number unique sequence of digits assigned to a telephone subscription

A telephone number is a sequence of digits assigned to a fixed-line telephone subscriber station connected to a telephone line or to a wireless electronic telephony device, such as a radio telephone or a mobile telephone, or to other devices for data transmission via the public switched telephone network (PSTN) or other public and private networks.

In the administration of the North American Numbering Plan, central office code protection was a numbering policy intended to ensure that the same local telephone number was not assigned in both of a pair of adjacent communities on opposite sides of an area code boundary. Its primary purpose was initially to preserve seven-digit dialing of local calls across a common area code boundary in border communities.

References

  1. ↑ Jordan, Mary; Quimpo, Margie G. (September 23, 1990). "Territorial Telephones; On Oct. 1, Local Calls Will Get Complicated". The Washington Post. p. 1.
  2. ↑ "Bellcore Letter IL-90/12-049" (PDF). North American Numbering Plan Administration. Neustar. Retrieved June 21, 2013.
  3. ↑ "Bellcore Letter IL 96/06-009" (PDF). North American Numbering Plan Administration. Neustar. Retrieved 21 June 2013.
  4. ↑ "New area code for eastern Maryland". The Baltimore Sun. November 1, 1991. p. 1A.
Maryland area codes: 240/301, 410/443/667
North: 223/717, 412/724/878, 814
West: 202, 304/681, 540, 571/703 area codes 240/301 East: 410/443/667
South: 804, 304/681
District of Columbia area codes: 202
Pennsylvania area codes: 215/267/445, 223/717, 272/570, 412, 484/610, 724, 814, 878
Virginia area codes: 276, 434, 540, 571/703, 757, 804
West Virginia area codes: 304/681
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