Image:Area code 202.svg, 350px, The red area is the

District of Columbia Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and Federal district of the United States, federal district of the United States. The city is on the Potomac River, across from ...

, served by area codes 202 and 771. poly 0 50 49 54 103 84 111 88 101 107 118 130 143 139 179 140 211 188 238 203 260 240 259 248 248 250 255 262 253 357 1 357 Area codes 571 and 703 poly 1 1 0 45 52 48 117 84 109 109 121 127 180 136 199 164 254 112 345 204 264 286 258 358 420 358 420 1 Area codes 301, 240, and 227 desc bottom-left

Area Area is the measure of a region's size on a surface. The area of a plane region or ''plane area'' refers to the area of a shape or planar lamina, while '' surface area'' refers to the area of an open surface or the boundary of a three-di ...

codes 202 and 771 are telephone

area code A telephone numbering plan is a type of numbering scheme used in telecommunication to assign telephone numbers to subscriber telephones or other telephony endpoints. Telephone numbers are the addresses of participants in a telephone network, rea ...

s in the

North American Numbering Plan The North American Numbering Plan (NANP) is an integrated 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, World Numbering Zone ...

(NANP) for

Washington, D.C. Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and federal district of the United States. The city is on the Potomac River, across from Virginia, and shares land borders with ...

Area code 202 was one of the

original North American area codes The original North American area codes were established by the American Telephone and Telegraph Company (AT&T) in 1947. The assignment was in accord with the design of a uniform nationwide telephone numbering plan that supported the goal of dialin ...

established in October 1947 by the American Telephone and Telegraph Company (AT&T). After the State of New Jersey with

area code 201 Area codes 201 and 551 are telephone area codes in the North American Numbering Plan (NANP) in the U.S. State of New Jersey. Area code 201 was the area code assigned to the entire state of New Jersey in 1947, when the North American area code s ...

, the District of Columbia was the second numbering plan area (NPA). Area code 771 was added to the numbering plan area in April 2021 in creation of an

overlay complex 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 Numbe ...

to mitigate impending telephone number shortages.

History

Since the creation of the first nationwide

telephone numbering plan A telephone numbering plan is a type of numbering scheme used in telecommunication to assign telephone numbers to subscriber telephones or other telephony endpoints. Telephone numbers are the addresses of participants in a telephone network, reach ...

in 1947, most of the inner ring of the Washington metropolitan area has been a single local calling area, the Washington Metropolitan Exchange Area (WMEA). This is despite the fact that the WMEA was split between three numbering plan areas (NPAs): the District's 202,

301 __NOTOC__ Year 301 ( CCCI) was a common year starting on Wednesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Postumius and Nepotianus (or, less frequently, year 1054 ''Ab urbe condita''). The denominatio ...

in southern

Maryland Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It borders the states of Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east ...

, and

703 __NOTOC__ Year 703 ( DCCIII) was a common year starting on Monday of the Julian calendar, the 703rd year of the Common Era (CE) and Anno Domini (AD) designations, the 703rd year of the 1st millennium, the 3rd year of the 8th century, and the ...

Northern Northern may refer to the following: Geography * North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating ...

Virginia Virginia, officially the Commonwealth of Virginia, is a U.S. state, state in the Southeastern United States, Southeastern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States between the East Coast of the United States ...

. From the 1950s to 1990, it was possible to complete local calls in the WMEA with only seven digits. The entire WMEA was reachable via long-distance services by dialing area code 202, for which purpose AT&T Long Lines had established cross-referenced operator routing codes for all affected central offices. This scheme was implemented via a system of central office code protection, in which central offices in the three numbering plan areas could not duplicate any central office prefixes for any of the three area codes in the WMEA. For example, if the 202-574 exchange was in use in the District, the corresponding 703-574 or 301-574 exchange could only be assigned a safe distance from the metropolitan area, such as southwestern Virginia or the

Eastern Shore of Maryland The Eastern Shore of Maryland is a part of the U.S. state of Maryland that lies mostly on the east side of the Chesapeake Bay. Nine counties are normally included in the region. The Eastern Shore is part of the larger Delmarva Peninsula that Ma ...

. By spring 1990,

C&P Telephone The Chesapeake and Potomac Telephone Company, usually known as C&P Telephone, is a former d/b/a name for four Bell Operating Companies providing service to Washington, D.C., Maryland, West Virginia, and Virginia. Today, three of the companies ar ...

(later part of Bell Atlantic and now

Verizon Verizon Communications Inc. ( ), is an American telecommunications company headquartered in New York City. It is the world's second-largest telecommunications company by revenue and its mobile network is the largest wireless carrier in the ...

), the Regional Bell Operating Company for the District, advised the

North American Numbering Plan Administration The North American Numbering Plan (NANP) is an integrated 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, World Numbering Zone ...

(NANPA) that the last

interchangeable central office code Interchangeability can refer to: *Interchangeable parts Interchangeable parts are parts (wikt:component#Noun, components) that are identical for practical purposes. They are made to specifications that ensure that they are so nearly identical t ...

in the area would be assigned in the second half of the year. The only remaining prefixes could not be assigned without eliminating seven-digit dialing in the region, leading C&P to terminate the central office code protection arrangement to make additional prefixes available for use. This change was implemented in a permissive dialing period from April 1, 1990, to October 1, 1990, at which time all home-NPA (HNPA) local calls maintained seven-digit dialing; all HNPA direct-dialed toll calls, required ''1'' and ten digits; foreign-NPA (FNPA) local calls were dialed with just the ten-digit number; FNPA direct dialed calls required dialing ''1'' and ten digits. Operator-assisted calls were all dialed as ''0'' and ten digits. The end of central office code protection was intended to allow number blocks to be assigned in the Washington area that could not previously be assigned under the previous system. However, it did not provide enough relief to meet demand on either side of the

Potomac River The Potomac River () is in the Mid-Atlantic (United States), Mid-Atlantic region of the United States and flows from the Potomac Highlands in West Virginia to Chesapeake Bay in Maryland. It is long,U.S. Geological Survey. National Hydrography D ...

. By the end of 1990, the Chesapeake and Potomac Telephone Company of Maryland determined that 301 was approaching exhaustion even with the end of central office code protection. It filed to assign

area code 410 __NOTOC__ Year 410 (CDX) was a common year starting on Saturday of the Julian calendar. At the time, it was known as the Year after the Consulship of Honorius and Theodosius (or, less frequently, year 1163 ''Ab urbe condita''). The denominatio ...

to most of Maryland from the

Baltimore Baltimore is the most populous city in the U.S. state of Maryland. With a population of 585,708 at the 2020 census and estimated at 568,271 in 2024, it is the 30th-most populous U.S. city. The Baltimore metropolitan area is the 20th-large ...

area eastward, effective October 5, 1991. In Virginia, the delay amounted to six years, until 1996, when

area code 540 Image:Area code 540.png, 400px, The area colored red indicates the northern region of Virginia served by area code 540 poly 391 103 368 103 343 148 324 152 325 160 317 164 309 174 311 177 302 178 364 181 385 161 Area codes 757 and 948 poly 3 ...

was installed for the western portion of the old 703 territory; permissive dialing ended January 27, 1996. The region's continued growth in the 1990s ultimately led to both suburban area codes being overlaid, with area code 240 overlaying 301 in 1997, and area code 571 overlaying 703 in 2000. With 202 facing exhaustion in late 2022, the

North American Numbering Plan Administrator The North American Numbering Plan (NANP) is an integrated 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, World Numbering Zone ...

announced in October 2020 the addition of area code 771 to the District of Columbia. The Public Service Commission approved a plan to phase in the new area code over a 13-month period. The installation of a second area code required transition to

ten-digit dialing Ten-digit dialing is a telephone dialing procedure in the countries and territories of the North American Numbering Plan (NANP). It is the practice of including the area code of a telephone number when Dialling (telephony), dialing to initiate a t ...

for all calls within the District. The overlay implementation commenced with a permissive dialing period from April 10, 2021, to October 9, 2021, during which ten-digit dialing of 202-telephone numbers was optional. The first central office code assignments for 771 took place on November 8, 2021, for central office code 777, and on November 9 for 888.

Local calling

Even with the implementation of ten-digit dialing in the Washington metro, much of the Washington area is still a single local calling area. The District is the center of one of the largest toll-free calling zones in the eastern United States, covering large portions of Virginia and Maryland. Areas such as

Alexandria Alexandria ( ; ) is the List of cities and towns in Egypt#Largest cities, second largest city in Egypt and the List of coastal settlements of the Mediterranean Sea, largest city on the Mediterranean coast. It lies at the western edge of the Nile ...

Arlington Arlington most often refers to: *Arlington, Virginia **Arlington National Cemetery, a United States military cemetery *Arlington, Texas Arlington may also refer to: Places Australia *Arlington light rail station, on the Inner West Light Rail in S ...

, Fairfax,

Falls Church Falls Church City is an independent city in the Commonwealth of Virginia, United States. As of the 2020 census, the population was 14,658. Falls Church is part of both Northern Virginia and the Washington metropolitan area. As of 2020, it has ...

, McLean and Tysons in Virginia ( 703/571) and Rockville,

Gaithersburg Gaithersburg ( ) is a city in Montgomery County, Maryland, United States. At the time of the 2020 United States census, Gaithersburg had a population of 69,657, making it the third-largest incorporated city and the ninth-most populous communit ...

, Upper Marlboro, Bethesda and Landover in MarylandLocal calling guide: Washington Zone 4, MD
/ref> ( 301/240) are a local call to Washington.

References

External links

{{coord, 38, 54, N, 77, 2, W, display=title

202 Year 202 ( CCII) was a common year starting on Friday of the Julian calendar. At the time, it was known as the Year of the Consulship of Severus and Antoninus (or, less frequently, year 955 ''Ab urbe condita''). The denomination 202 for this yea ...

Telecommunications-related introductions in 1947

Washington, D.C.

History

Local calling

See also

References

External links