Area code 206 is a 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 ...

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 the

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its so ...

of Washington. The numbering plan area (NPA) includes

Seattle Seattle ( ) is the most populous city in the U.S. state of Washington and in the Pacific Northwest region of North America. With a population of 780,995 in 2024, it is the 18th-most populous city in the United States. The city is the cou ...

and most of its innermost suburbs. This includes such suburbs as

Shoreline A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...

and Lake Forest Park; Mercer, Bainbridge, and Vashon Islands; and portions of metropolitan Seattle from

Des Moines Des Moines is the List of capitals in the United States, capital and List of cities in Iowa, most populous city in the U.S. state of Iowa. It is the county seat of Polk County, Iowa, Polk County with parts extending into Warren County, Iowa, Wa ...

to Woodway. On June 10, 2025, the numbering plan area will be converted to 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 ...

with area code 564, which also overlays

360 360 may refer to: * 360 (number) * 360 AD, a year * 360 BC, a year * 360 degrees, a turn Businesses and organizations * 360 Architecture, an American architectural design firm * Ngong Ping 360, a tourism project in Lantau Island, Hong Kong ...

History

Area code 206 was one of the original North American area codes assigned in 1947, when it served the entire state of Washington. In 1957, area code 509 was assigned for the eastern two-thirds of Washington in a flash-cut, with the split roughly following the

Cascade Mountains The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as many of those in the ...

. Despite western Washington's growth in the second half of the 20th century, this configuration remained in place for 38 years. By the start of the 1990s, however, 206 was nearing exhaustion of central office codes from proliferation of cell phones, pagers, and fax machines. On January 15, 1995, most of the old 206 territory outside of the Seattle/ Tacoma area was split off with

area code 360 Area code 360 is a telephone area code in the North American Numbering Plan (NANP) for the part of Washington state outside metropolitan Seattle and west of the Cascade Mountains. The numbering plan area (NPA) serves all of western Washington out ...

, which was one of the first two area codes not conforming to the then-traditional N0X/N1X format. Numerous residents in the Seattle exurbs protested about no longer being associated with 206, leading US West, now part of

Lumen Technologies Lumen Technologies, Inc. (formerly CenturyLink, Inc.) is an American telecommunications company headquartered in Monroe, Louisiana, which offers communications, network services, security, cloud solutions, voice and managed services through ...

, to return these to 206 shortly after the split. As part of the reintegration, the cities of

and Woodway were both split between the new area codes, required by the capacity of the switching centers. However, western Washington would have likely needed another area code before the end of the decade, as 206 was still exceeding threshold utilization even after the 360 split. The return of the Seattle exurbs, combined with the continued proliferation of cell phones, faxes, and pagers, hastened a three-way split of the 206 territory, effective on April 25, 1997. The southern portion, including Tacoma, received area code 253, while the northern portion, including Everett and the Eastside, was assigned area code 425. On June 15, 2023, the WUTC approved the expansion of the

564 to the 206 area before central office code exhaustion occurs in 2025. Area code 564 had served the 360 numbering plan area since 2017. 564 planning specifies its expansion to numbering plan areas 253 and 425 once necessary. However,

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 ...

has been mandatory for all of Washington west of the Cascades since 2017. The in-service date for the 206/564 overlay is June 10, 2025, at which time providers may begin activating central office codes for area code 564 in numbering plan area 206, provided that all 206 central office codes have been allocated.

References

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206 Year 206 ( CCVI) was a common year starting on Wednesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Umbrius and Gavius (or, less frequently, year 959 ''Ab urbe condita''). The denomination 206 for this y ...

Telecommunications-related introductions in 1947

History

See also

References