Area codes 314 and 557 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) in 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 ...

Missouri Missouri (''see #Etymology and pronunciation, pronunciation'') is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it border ...

, 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 The Mississippi River is the main stem, primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri River, Missouri. From its traditional source of Lake Ita ...

to the east, 314 is adjacent to

area code 618 Area codes 618 and 730 are telephone area codes in the North American Numbering Plan (NANP) for southern Illinois. The numbering plan area (NPA) comprises one hundred and twenty-six municipalities, such as Carbondale, Cairo, Belleville, East ...

, which serves

southern Illinois Southern Illinois is a region of the U.S. state of Illinois comprising the southern third of the state, principally south of Interstate 70. Part of downstate Illinois, it is bordered by the two List of U.S. rivers by discharge, most voluminous ri ...

and most of

Metro East The Metro East is an urban area in Southern Illinois, United States that contains the eastern and northern urban, suburban, and exurban areas on the Mississippi River in Greater St. Louis. It encompasses eight Illinois counties and constitutes ...

. Area code 557 was added to the 314 numbering plan area on August 12, 2022, to form an overlay numbering plan.

History

When the

American Telephone and Telegraph Company AT&T Corporation, an abbreviation for its former name, the American Telephone and Telegraph Company, was an American telecommunications company that provided voice, video, data, and Internet telecommunications and professional services to busi ...

(AT&T) created a universal North American

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 ...

for

Operator Toll Dialing Operator Toll Dialing was a telephone call routing and toll-switching system for the Bell System and the independent telephone companies in the United States and Canada that paved the way for Direct Distance Dialing (DDD) by telephone service subsc ...

in 1947, and assigned 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 ...

to numbering plan areas (NPAs), Missouri was divided into two NPAs, which received the area codes 314 and 816. Area code 314 identified the eastern part of the state, from the northeast corner of the state at the Illinois border along a southwestern line near Columbia and

Jefferson City Jefferson City, informally Jeff City, is the List of capitals in the United States, capital of the U.S. state of Missouri. It had a population of 43,228 at the 2020 United States census, ranking as the List of cities in Missouri, 16th most popu ...

to the center of the state, and continuing southeast into the east side of the West Plains area to the Arkansas state line. The largest city of the area code was St. Louis on the Mississippi river in the east. By 1995, the telephone subscriber base had experienced substantial growth, threatening the exhaustion of the numbering pool. Relief planning entailed the division of the numbering plan area to create a new area code, 573, for most areas outside of the St. Louis metropolitan area, which would retain area code 314. The area code split became effective at day end of January 7, 1996, with a permissive dialing period commencing until July 7, 1996, during which the new numbering plan area could be dialed with both area codes. Although area code splits were intended as long-term solutions, within only two years, 314 was close to exhaustion once again due to the proliferation of cell phones, fax machines and pagers in St. Louis. As a result, 314 was reduced to include only the exchanges of Chestnut, Jefferson, Prospect, Flanders, Forest, Mission, Melrose, Webster Groves, Parkview, Evergreen, Riverview, Ferguson, Overland, Ladue, Kirkwood, Sappington, Mehlville, Oakville, Creve Coeur, Bridgeton, Hazelwood, Florissant, and Spanish Lake in the core of the St. Louis area. All other exchanges were reassigned to the new area code 636, effective May 22, 1999, with the permissive dialing period ending on February 26, 2000. On October 24, 2000, the Missouri Public Service Commission announced plans to add a second area code for the 314 numbering plan area, creating an overlay, but postponed the implementation date (May 5, 2002) indefinitely on September 25, 2001, when the commission determined no immediate need for additional central office prefixes. Conservation measures, such as

number pooling Telephone number pooling, thousands-block number pooling, or just number pooling, is a method of allocating telephony numbering space of the North American Numbering Plan in the United States. The method allocates telephone numbers in blocks of 1,0 ...

, mitigated the immediate need for relief. More than twenty years after that announcement, area code 557 was overlaid on August 12, 2022, as the available numbers in 314 neared exhaustion. Prior to October 2021, area code 314 had telephone numbers assigned for the central office code 988. In 2020, ''988'' was designated nationwide as a dialing code for the

National Suicide Prevention Lifeline The Suicide and Crisis Lifeline in the United States, or Suicide Crisis Helpline in Canada, and formerly known as the National Suicide Prevention Lifeline, is a suicide prevention and crisis help line to a network of a large number of crisis ce ...

, which created a conflict for exchanges that permit seven-digit dialing. This area code was therefore scheduled to 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 ...

by October 24, 2021.

References

External links

{{Coord, 38.62, -90.22, format=dms, display=title, type:adm3rd_region:US-MO 314 St. Louis St. Louis County, Missouri 314 Telecommunications-related introductions in 1947

History

See also

References

External links