Area code 564 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 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 international callin ...

(NANP) for

Western Washington Western Washington is a region of the United States defined as the area of Washington state west of the Cascade Mountains. This region is home to the state's largest city, Seattle, the state capital, Olympia, and most of the state's residents. The ...

state, including the city of

Seattle Seattle ( ) is a seaport city on the West Coast of the United States. It is the seat of King County, Washington. With a 2020 population of 737,015, it is the largest city in both the state of Washington and the Pacific Northwest regio ...

. The area code serves an overlay complex for a region that comprises the numbering plan areas 206,

253 __NOTOC__ Year 253 ( CCLIII) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Volusianus and Claudius (or, less frequently, year 100 ...

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

, and 425.

History

Area code 564 was originally proposed and approved in 2000, but was not implemented until July 29, 2017. Initially, it was implemented as a concentrated overlay for the 360 area, comprising all of western Washington outside of the core of the Seattle/Tacoma metropolitan area. While it is to be extended to include other area codes in the region as they exhaust, its implementation has made

ten-digit dialing 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 telep ...

mandatory in all of western Washington. In 1999, area code 564 was proposed as an overlay of 360. This was slated for implementation on July 29, 2000. Later, the

Washington Utilities and Transportation Commission The Washington Utilities and Transportation Commission (UTC) is a three-member board appointed by the Governor of Washington and confirmed by the Washington State Senate to six-year terms. The purpose of the UTC is to regulate the rates, services, ...

(WUTC) determined that the actual increase in need for new numbers in 360 had fallen short of projections and so it postponed the overlay until at least February 2001. In May 2000, the commission projected that the metropolitan Seattle area codes (206, 253, and 425) would also soon exhaust their number pools, and it expanded the 564 plan to include those areas as well. By the summer, however, that was determined not to be immediately necessary. The overlay was then planned for application on October 20, 2001. On August 22, 2001, the WUTC announced that increased efficiency in the reuse of the existing number pool meant that the immediate need for the new area code had subsided. Part of that was also attributed to a downturn in the telecommunications sector. The commission put off implementation until no earlier than October 20, 2002. Since the development of the initial plan for the area code, the WUTC and the

NANPA 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 international calling ...

have rebuffed the telephone companies' request for a new area code and instead directed them to actively share and efficiently use the number blocks that had already been assigned. That refers mainly to the practice of

number pooling Number pooling is a method of reallocating telephony numbering space in the North American Numbering Plan, primarily in growth areas in the United States. Instead of allocating blocks of ten thousand numbers to each carrier in each community, a bl ...

, which allocates a single

telephone exchange A telephone exchange, telephone switch, or central office is a telecommunications system used in the public switched telephone network (PSTN) or in large enterprises. It interconnects telephone subscriber lines or virtual circuits of digital syst ...

prefix in ten blocks of one thousand telephone numbers for more efficient allocation, rather than assigning a prefix's whole numbering space (10,000 numbers) to one carrier in the a single

rate center In the North American Numbering Plan, a rate center (rate centre in Canada) is a geographically-specified area used for determining mileage and/or usage dependent rates in the public switched telephone network. Unlike a wire center (which is the ...

. The WUTC took further steps to decrease the need for new number blocks in 360 and 509 and head off the need for new area codes, including aggressive reclamation of unused and underused number blocks and exchanges. The introduction of mandatory

local Local may refer to: Geography and transportation * Local (train), a train serving local traffic demand * Local, Missouri, a community in the United States * Local government, a form of public administration, usually the lowest tier of administrat ...

and wireless number portability (a prerequisite for number pooling) has also served to stem the demand for new numbers and thus new area codes. According to the WUTC's estimate , the earliest projection for any Western Washington area code to be exhausted is 2018 for area code 360. The other codes are not expected to exhaust before 2025. On July 29, 2017, ten-digit dialing became mandatory for all local calls in Western Washington. Until then, Seattle had been one of the few major American cities with

seven-digit dialing 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 wh ...

. Since September 30, 2017, telephone numbers with the area code 564 have been issued in the existing number plan area 360. Once other codes in Western Washington are exhausted, 564 numbers will be assigned in those areas as well. Area code 206 is anticipated to be the next code overlaid by 564, which is projected in 2027.

References

External links

{{DEFAULTSORT:Area Code 564 564 564