Area codes 301, 240, and 227

Last updated
Maryland consists of the red and blue areas. The red area has area codes 227, 240 and 301. Area code 301.svgArea code 484Area code 304/681
Maryland consists of the red and blue areas. The red area has area codes 227, 240 and 301.

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.

Contents

Area code 301 was the first area code for all of Maryland, from 1947, when the area code system was created, until 1991, when everything from Baltimore eastward split off as area code 410. In 1997, area code 240 was added as an overlay area code for the 301 territory. On June 14, 2023, a third overlay code, 227, was added to provide more central office prefixes for new telephone numbers.

History

Area code 301 was one of the original North American area codes when the American Telephone and Telegraph Company (AT&T) established a new, nationwide telephone numbering plan in 1947. The area code served the entire state of Maryland.

Much of the Washington metropolitan area is part of a local calling area which is centered on the District's area code 202, and also extends into the suburban area in southern Maryland with 301 and Northern Virginia with area code 703. From 1947 to 1990, it was possible to dial any other telephone number in the metro area as a local call with only seven digits, not using an area code, irrespective of the home area code. The entire metro area was also reachable via long-distance services by dialing area code 202, for which purpose AT&T had established cross-referenced operator routing codes for all affected central offices. [1] For example, if 202-574 numbers were in use in the District or 703-574 numbers were in use in Northern Virginia, the corresponding 301-574 numbering block could only be assigned in areas considered a safe distance away from the capital, such as the Eastern Shore of Maryland.

Ten-digit dialing

By the end of the 1980s, the Washington metropolitan area was running out of assignable prefixes for new central offices on both sides of the Potomac River. The only unassigned prefixes were unavailable due to the central office code protection that maintained seven-digit dialing in the metro-area. Assignment of these prefixes would require dialing an area code. The three local operating companies of the Chesapeake and Potomac Telephone Company (C&P Telephone, later part of Bell Atlantic and now Verizon) cooperated in ending code protection for the Washington area on October 1, 1990. Ten-digit dialing was now required for all local calls between Maryland, the District of Columbia, and Virginia. [2] Area code 202 was no longer usable for suburban points. Local calls within Maryland did not require the area code. [3] Permissive dialing using the old dialing procedures continued from April 1 through October 1, 1990. [4]

410-split

Despite the overall growth of the Baltimore–Washington metropolitan area, By the end of the 1980s, it became apparent that terminating central office code protection in the Washington area could not free up sufficient resources north of the Potomac River to stave off the immediate need for a new area code.

In mitigation action, Baltimore and the Eastern Shore were reassigned from area code 301 to area code 410 on November 1, 1991, to form a new numbering plan area. [5] [6] The area code split largely followed metropolitan area lines. There were a few exceptions, such as in Howard County, which is often recognized as part of the Baltimore metropolitan area, a small portion of the county remained in 301, while the rest of the county was reassigned to 410. [7]

When an area code is split, the largest city, in this case Baltimore, in the old numbering plan area typically retains the existing area code to minimize expense for changing telephone numbers. However, Bell Atlantic wanted to spare the large number of federal agencies on the Maryland side of the Washington area from the expense and disruption of a new area code. While Maryland would have likely needed another area code due to the growth of the Baltimore-Washington corridor, it is likely that a split would have been delayed had more 301 numbers been available for use in Baltimore.

240-overlay

Although the area code split was intended as a long-term solution, within four years 301 was close to exhaustion due to the proliferation of cell phones and pagers, especially in the Washington suburbs. In relief action, area code 240 was introduced on June 1, 1997, to form the state's first overlay. [8] Overlays were a new concept at the time, and met with some resistance due to the requirement for ten-digit dialing. [9] It was decided to create an overlay rather than split the region into two numbering plan areas to avoid assigning a new area code to 1.2 million existing telephone numbers. [10] At the time, it was predicted that it would take until 2008 to exhaust area code 240. [11]

227-overlay

A September 2022 study projected that the 301/240 numbering plan area (NPA) would suffer central office code exhausted between April and June 2023. [12] Area code 227 was already approved as an all-services distributed overlay since January 3, 2001 for the 301/240 NPA. [13] [14] The new area code went into service on June 14, 2023, at which time activation of new central office codes could begin, once all assignable central office codes in 240/301 had been exhausted.

Service area

The numbering plan area 301/240/227 include the counties of Allegany, Charles, Garrett, Montgomery, Prince George's, St. Mary's and Washington counties, most of Frederick County, [lower-alpha 1] western Howard County, [lower-alpha 1] and slivers of southwestern Carroll County [lower-alpha 1] and western Anne Arundel County. [lower-alpha 1]

Local calls require ten-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.
    • In Anne Arundel County, Laurel exchanges 210, 317, 490, 497, 498, 596, 604, 725, and 778 and Marlboro exchange 952 remained area code 301. The rest of the county was assigned area code 410.
    • In Carroll County Mount Airy exchange 829 remained area code 301. The rest of the county was assigned area code 410.
    • In Howard County, Mount Airy exchange 829 and Laurel exchanges 210, 317, 490, 497, 598, 604, 725, and 776 remained area code 301. The rest of the county was assigned area code 410.
    • Most of Frederick County remained area code 301. Only Union Bridge exchange 775 and New Windsor exchange 635 were assigned area code 410. [15]

Related Research Articles

<span class="mw-page-title-main">North American Numbering Plan</span> Integrated telephone numbering plan of twenty North American countries

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 with the NANP.

<span class="mw-page-title-main">Area codes 314 and 557</span> Telephone area code for St. Louis, Missouri

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.

In telecommunications, an area code overlay complex is a telephone numbering plan that assigns multiple area codes to the same 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 exclusive method of area code relief since 2007.

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.

<span class="mw-page-title-main">Area codes 561 and 728</span> Telephone area code in Palm Beach County, Florida

Area codes 561 and 728 are telephone area codes in the North American Numbering Plan (NANP) for Palm Beach County in the U.S. state of Florida. 561 was created on May 13, 1996, in a split of area code 407. The numbering plan area (NPA) comprises nearly every major city in the county, the largest of which being West Palm Beach, Boca Raton, Wellington, Boynton Beach, Jupiter, Delray Beach, and Belle Glade. On March 10, 2023, area code 728 was added to the same numbering plan area to form an all-services distributed overlay.

<span class="mw-page-title-main">Area codes 920 and 274</span> Area code in eastern Wisconsin, United States

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.

<span class="mw-page-title-main">Area code 564</span> Telephone area code for western Washington, United States

Area code 564 is a telephone overlay area code in the North American Numbering Plan (NANP) for Western Washington state, including metropolitan Seattle. The area code was first proposed in 1999 to relieve telephone number shortages in area code 360, but implementation was delayed until 2017, when it was installed for an overlay complex that comprises only the numbering plan area 360. Neighboring area codes 206, 253, and 425 were slated for expansion of the overlay upon exhaustion of central office codes in each NPA. In 2023, area code 206 was approved for expansion with a guide line for preparation of inclusion of at least nine months. Ten-digit dialing has been mandatory in all of western Washington since July 29, 2017.

<span class="mw-page-title-main">Area codes 909 and 840</span> Area codes in southern California, United States

Area codes 909 and 840 are telephone area codes in the North American Numbering Plan for the far-eastern part of Los Angeles County southwestern San Bernardino County, and a small portion of Riverside County in the U.S. state of California. Area code 909 was created on November 14, 1992, in an area code split of 909, and 840 was added to the numbering plan area to form an overlay complex effective February 23, 2021. While most of western Riverside County now uses Area code 951, some residents in Eastvale and Corona were allowed to keep the 909 area code after the split in 2004.

<span class="mw-page-title-main">Area codes 202 and 771</span> Area codes for Washington, D.C.

Area codes 202 and 771 are telephone area codes in the North American Numbering Plan (NANP) for Washington, D.C.

<span class="mw-page-title-main">Area codes 608 and 353</span> Telephone area code for southwestern Wisconsin

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.

<span class="mw-page-title-main">Area codes 813 and 656</span> Telephone area code for Tampa, Florida

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.

<span class="mw-page-title-main">Area codes 610, 484, and 835</span> Telephone area codes in Pennsylvania, United States

Area codes 610, 484, and 835 are telephone area codes in the North American Numbering Plan (NANP) for the eastern and southeastern regions of Pennsylvania. The numbering plan area (NPA) includes regions to the west of Philadelphia and the cities Allentown, Bethlehem, and Reading. It includes much of the Delaware Valley, including almost all of Delaware County, most of the Philadelphia Main Line, and all of the Lehigh Valley.

<span class="mw-page-title-main">Area codes 410, 443, and 667</span> Telephone area codes for east Maryland

Area codes 410, 443, and 667 are telephone area codes in the North American Numbering Plan (NANP) for the eastern half of the U.S. state of Maryland. The numbering plan area (NPA) includes the Baltimore metropolitan area and the Eastern Shore. The three area codes are overlay codes for one numbering plan area, among which 410 was the initial area code for the NPA, when it was split from area code 301 in 1991. 443 and 667 found assignment primarily in cellular service and for competitive local exchange carriers, such as Comcast and Cavalier Telephone, when introduced, but have since become universal in carrier availability.

<span class="mw-page-title-main">Area code 334</span> Area code for southeastern Alabama, United States

Area code 334 is a telephone area code in the North American Numbering Plan (NANP) for southeastern Alabama. It was created on January 15, 1995, in an area code split from area code 205. It was the first new area code in Alabama since the announcement of the area code system in 1947. To permit a transition period for the reconfiguration of equipment, such as computers and fax machines, use of area code 205 continued in the 334 region through May 13, 1995.

<span class="mw-page-title-main">Area code 660</span> Telephone area code for northern and western Missouri, United States

Area code 660 is the telephone area code in the North American Numbering Plan (NANP) for the northern and western part of the U.S. state of Missouri. It was created on October 12, 1997, in a split of the 816 numbering plan area (NPA)

<span class="mw-page-title-main">Area codes 513 and 283</span> Area code in southwest Ohio, US

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.

<span class="mw-page-title-main">Area codes 816 and 975</span> Area code in northwestern Missouri, United States

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.

<span class="mw-page-title-main">Area codes 703 and 571</span> Telephone area codes for Northern Virginia, United States

Area codes 703 and 571 are telephone area codes in the North American Numbering Plan (NANP) 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, and Prince William counties. Area code 703 was created as one of the eighty-six original North American area codes in October 1947, and originally served the entire Commonwealth of Virginia. Area code 571 was created on March 1, 2000, to form an overlay plan with 703.

References

  1. ↑ AT&T Long Lines, Distance Dialing Reference Guide (April 1974) This was implemented via a system of central office code protection, meaning that no central office code in the metro area could exist in more than a single central office.
  2. ↑ "Area Codes Needed to Call Between Md., D.C., Va." The Baltimore Sun. October 1, 1990. p. 2B.
  3. ↑ Jordan, Mary; Quimpo, Margie G. (September 23, 1990). "Territorial Telephones; On Oct. 1, Local Calls Will Get Complicated". The Washington Post. p. 1.
  4. ↑ NANPA Bellcore Information Letter IL-90/04-003
  5. ↑ Muth, Charlie (November 17, 1990). "Shore to Get New Area Code". The Daily Times (Salisbury, Maryland). p. 1, 4.
  6. ↑ Hetrich, Ross (October 25, 1991). "New Area Code 410 Starts Nov. 1 in Half of State". The Baltimore Evening Sun. p. C12.
  7. ↑ "Bellcore Letter IL-90/12-049" (PDF). North American Numbering Plan Administration. Neustar. Retrieved June 21, 2013.
  8. ↑ "Bellcore Letter IL 96/06-009" (PDF). North American Numbering Plan Administration. Neustar. Retrieved 21 June 2013.
  9. ↑ Yates, Jennifer C. (April 22, 1997). "Maryland Gets Read for 10-digit Dialing". Associated Press. The Star-Democrat (Easton, Maryland). p. A1.
  10. ↑ "Ready for 10-digit Stroll?". The Daily Times (Salisbury, Maryland). January 23, 1997. p. 4.
  11. ↑ Pemberton, Mary (May 2, 1997). "10-digit Dialing Comes to Maryland". Associated Press. The Gettysburg Times (Gettysburg, Pennsylvania). p. A3.
  12. ↑ "2022-1 NRUF and NPA Exhaust Analysis" (PDF). North American Numbering Plan Administrator. April 21, 2021. Retrieved July 15, 2021.
  13. ↑ "Planning Letter PL-603: NPA 227 and 240/301 All-Services Overlay (Maryland)" (PDF). NANPA. 2022-09-27. Retrieved 2023-05-27.
  14. ↑ Duffy, Ken (September 28, 2022). "New Area Code Coming to Parts of Maryland". WBAL .
  15. ↑ "New area code for eastern Maryland". The Baltimore Sun. November 1, 1991. p. 1A.
Maryland area codes: 301/240/227, 410/443/667
North: 717/223, 412/724/878, 814/582
West: 202/771, 304/681, 540/826, 703/571 area codes 301/240/227 East: 410/443/667
South: 804/686, 304/681
District of Columbia area codes: 202/771
Pennsylvania area codes: 215/267/445, 412, 570/272, 610/484/835, 717/223, 724, 814/582, 878
Virginia area codes: 276, 434, 540/826, 703/571, 757/948, 804/686
West Virginia area codes: 304/681
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.