A TELEPHONE NUMBER is a sequence of digits assigned to a fixed-line
telephone subscriber station connected to a telephone line or to a
wireless electronic telephony device, such as a radio telephone or a
mobile telephone, or to other devices for data transmission via the
public switched telephone network (PSTN) or other private networks.
A telephone number serves as an address for switching telephone calls
using a system of destination code routing.
Telephone numbers are
entered or dialed by a calling party on the originating telephone set,
which transmits the sequence of digits in the process of signaling to
a telephone exchange . The exchange completes the call either to
another locally connected subscriber or via the PSTN to the called
Telephone numbers are assigned within the framework of a
national or regional telephone numbering plan to subscribers by
telephone service operators, which may be commercial entities,
state-controlled administrations, or other telecommunication industry
Telephone numbers were first used in 1879 in
Lowell, Massachusetts ,
when they replaced the request for subscriber names by callers
connecting to the switchboard operator . Over the course of telephone
history , telephone numbers had various lengths and formats, and even
included most letters of the alphabet in leading positions when
telephone exchange names were in common use until the 1960s.
Telephone numbers are often dialed in conjunction with other
signaling code sequences, such as vertical service codes , to invoke
special telephone service features.
* 1 Concept and methodology
* 2 U.S. history
* 2.1 Alphanumeric telephone numbers
* 4 Intercepted number
Special feature codes
* 6 In popular culture
* 7 See also
* 8 References
* 9 External links
CONCEPT AND METHODOLOGY
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When telephone numbers were first used they were very short, from one
to three digits, and were communicated orally to a switchboard
operator when initiating a call. As telephone systems have grown and
interconnected to encompass worldwide communication, telephone numbers
have become longer. In addition to telephones , they have been used to
access other devices, such as computer modems , pagers , and fax
machines . With landlines , modems and pagers falling out of use in
favor of all-digital always-connected broadband
Internet and mobile
phones , telephone numbers are now often used by data-only cellular
devices, such as some tablet computers , digital televisions , video
game controllers , and mobile hotspots , on which it is not even
possible to make or accept a call .
The number contains the information necessary to identify uniquely
the intended endpoint for the telephone call . Each such endpoint must
have a unique number within the public switched telephone network .
Most countries use fixed length numbers (for normal lines at least)
and therefore the number of endpoints determines the necessary length
of the telephone number. It is also possible for each subscriber to
have a set of shorter numbers for the endpoints most often used. These
"shorthand" or "speed calling" numbers are automatically translated to
unique telephone numbers before the call can be connected. Some
special services have their own short numbers (e.g.,
1-1-9 , 9-1-1
,1-0-0 , 1-0-1, 1-0-2, 0-0-0 , 9-9-9 ,
1-1-1 , and
1-1-2 being the
Emergency Services numbers for China, Japan, India, South Korea,
Taiwan and Sri Lanka; Canada and the United States; Australia and
Israel (Police); Israel (Paramedic); Israel (Fire); the United
Kingdom, Ireland, South Africa, Poland, Saudi Arabia, the United Arab
Emirates, Morocco, Macao, Bahrain, Qatar, Bangladesh, Botswana, Ghana,
Kenya, Hong Kong, Malaysia, Mauritius, Singapore, Zimbabwe, Trinidad,
Tobago; New Zealand; Kuwait and the European Union, respectively.)
The dialing plan in some areas permits dialing numbers in the local
calling area without using area code or city code prefixes. For
example, a telephone number in
North America consists of a three-digit
area code, a three-digit central office code, and four digits for the
line number. If the area has no area code overlays, seven-digit
dialing may be permissible for calls within the area, but some areas
have implemented mandatory ten-digit dialing .
Other special phone numbers are used for high-capacity numbers with
several telephone circuits , typically a request line to a radio
station where dozens or even hundreds of callers may be trying to call
in at once, such as for a contest. For each large metro area , all of
these lines will share the same prefix (such as 404 -741-xxxx in
Atlanta and 305 -550-xxxx in
Miami ), the last digits typically
corresponding to the station's frequency , callsign , or moniker .
In the international telephone network, the format of telephone
numbers is standardized by
E.164 . This code
specifies that the entire number should be 15 digits or shorter, and
begin with a country prefix . For most countries, this is followed by
an area code or city code and the subscriber number, which might
consist of the code for a particular telephone exchange . ITU-T
E.123 describes how to represent an international
telephone number in writing or print, starting with a plus sign ("+")
and the country code . When calling an international number from a
landline phone, the + must be replaced with the international call
prefix chosen by the country the call is being made from. Many mobile
phones allow the + to be entered directly, by pressing and holding the
GSM phones, or sometimes "*" for
The format and allocation of local phone numbers are controlled by
each nation's respective government, either directly or by sponsored
organizations (such as NANPA in the US or CNAC in Canada). In the
United States, each state's public service commission regulates, as
Federal Communications Commission
Federal Communications Commission . In Canada, which shares
the same country code with the U.S. (due to
Bell Canada 's previous
ownership by the U.S.-based
Bell System ), regulation is mainly
through the Canadian Radio-television and Telecommunications
Local number portability (LNP) allows a subscriber to request moving
an existing telephone number to another telephone service provider.
Number portability usually has geographic limitations, such as an
existing local phone company only being able to port to a competitor
within the same rate centre . Mobile carriers may have much larger
market areas, and can assign or accept numbers from any area within
Within most North American rate centres, local wireline calls are
free, while calls to all but a few nearby rate centres are considered
long distance and incur a per-minute toll. In a few large US cities,
as well as most points outside North America, local calls are not
flat-rated or "free" by default.
North American Numbering Plan
North American Numbering Plan
In the late 1870s, the Bell interests started utilizing their patent
with a rental scheme, in which they would rent their instruments to
individual users who would contract with other suppliers to connect
them; for example from home to office to factory.
Western Union and
the Bell company both soon realized that a subscription service would
be more profitable, with the invention of the telephone switchboard or
central office . Such an office was staffed by an operator who
connected the calls by personal names. Some have argued that use of
the telephone altered the physical layout of American cities.
The latter part of 1879 and the early part of 1880 saw the first use
of telephone numbers at
Lowell, Massachusetts . During an epidemic of
measles, the physician, Dr. Moses Greeley Parker , feared that
Lowell's four telephone operators might all succumb to sickness and
bring about paralysis of telephone service. He recommended the use of
numbers for calling Lowell's more than 200 subscribers so that
substitute operators might be more easily trained in such an
emergency. Parker was convinced of the telephone's potential, began
buying stock, and by 1883 he was one of the largest individual
stockholders in both the American
Telephone Company and the New
Telephone and Telegraph Company .
Even after the assignment of numbers, operators still connected most
calls into the early 20th century: "Hello, Central. Get me
Underwood-342." Connecting through operators or "Central" was the norm
until mechanical direct-dialing of numbers became more common in the
In rural areas with magneto crank telephones connected to party lines
, the local phone number consisted of the line number plus the ringing
pattern of the subscriber. To dial a number such as "3R122" meant
making a request to the operator the third party line (if making a
call off your own local one), followed by turning the telephone's
crank once, a short pause, then twice and twice again. Also common
was a code of long and short rings, so one party's call might be
signaled by two longs and another's by two longs followed by a short.
It was not uncommon to have over a dozen ring cadences (and
subscribers) on one line.
In the most areas of
North America , telephone numbers in
metropolitan communities consisted of a combination of digits and
letters, starting in the 1920s until the 1960s. Letters were
translated to dialed digits, a mapping that was displayed directly on
the telephone dial. Each of the digits 2 to 9, and sometimes 0,
corresponded to a group of typically three letters. The leading two or
three letters of a telephone number indicated the exchange name , for
example, EDgewood and IVanhoe, and were followed by 5 or 4 digits. The
limitations that these system presented in terms of usable names that
were easy to distinguish and spell, and the need for a comprehensive
numbering plan that enabled direct-distance dialing, led to the
introduction of all-number dialing in the 1960s.
The use of numbers starting in 555- (KLondike-5) to represent
fictional numbers in U.S. movies, television, and literature
originated in this period. The "555" prefix was reserved for telephone
company use and was only consistently used for directory assistance
(information), being "555-1212" for the local area. An attempt to dial
a 555 number from a movie in the real world will always result in an
error message when dialed from a phone in the United States. This
reduces the likelihood of nuisance calls. Also, QUincy(5-5555) was
used, because there was no Q available. Phone numbers were
traditionally tied down to a single location; because exchanges were
"hard-wired", the first three digits of any number were tied to the
geographic location of the exchange.
ALPHANUMERIC TELEPHONE NUMBERS
Telephone exchange names Face of a 1939 rotary
dial showing a 2L-4N style alphanumeric telephone number
LAkewood-2697. 2008 photo shows a hairdressing shop in Toronto
with an exterior sign showing the shop's telephone number in the old
two-letters plus five-digits format.
Until the early 1960s, many local telephone companies, as well as the
North American Numbering Plan
North American Numbering Plan of 1947, prescribed telephone number
formats that included the name of the central office to which each
telephone was connected. Traditionally, these names were often the
names of towns, villages, other locally significant names, but larger
communities that required more than one central office, may have used
other names for each central office, such as Main, East, West,
Central. Names were convenient to use and reduced errors when
telephone numbers were exchanged verbally between subscribers and
operators. When subscribers could dial themselves, the initial letters
of the names were converted to digits as displayed on the rotary dial.
Thus, telephone numbers contained one, two, or even three letters
followed by up to five numerals. Such numbering plans are called
2L-4N, or simply 2-4, for example, as shown in the photo of a
telephone dial of 1939 (right). In this example, LAkewood 2697,
indicates that a subscriber dialed the letters L and A, then the
digits 2, 6, 9, and 7 to reach this telephone in Lakewood, NJ (USA).
In December 1930,
New York City
New York City became the first city in the United
States to adopt the two-letter, five-number format (2L-5N), which
became the standard after
World War II
World War II , when the Bell System
administration designed the
North American Numbering Plan
North American Numbering Plan to prepare
United States and Canada for Direct Distance Dialing (DDD), and
began to convert all central offices to this format. This process was
complete by the early 1960s.
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Telephone numbers in the
In the UK , letters were assigned to numbers in a similar fashion to
North America, except that the letter O was allocated to the digit 0
(zero); digit 6 had only M and N. The letter Q was later added to the
zero position on British dials, in anticipation of direct
international dialing to Paris, which commenced in 1963. This was
necessary because French dials already had Q on the zero position, and
there were exchange names in the Paris region which contained the
Most of the
United Kingdom had no lettered telephone dials until the
introduction of Subscriber Trunk Dialing (STD) in 1958. Until then,
only the director areas (Birmingham, Edinburgh, Glasgow, Liverpool,
London and Manchester) and the adjacent non-director areas had the
lettered dials; the director exchanges used the three-letter,
four-number format. With the introduction of trunk dialing, the need
for all callers to be able to dial numbers with letters in them led to
the much more widespread use of lettered dials. The need for dials
with letters ceased with the conversion to all-digit numbering in
In the middle 20th century in
North America when a call could not be
completed, for example because the phone number was not assigned, had
been disconnected, or was experiencing technical difficulties, the
call was routed to an intercept operator who informed the caller. In
the 1970s this service was converted to Automatic Intercept Systems
which automatically choose and present an appropriate intercept
message . Disconnected numbers are reassigned to new users after the
rate of calls to them declines.
North America operator intercept was rare, and in most
cases calls to unassigned or disconnected numbers would result in a
recorded message or number-unobtainable tone being returned to the
SPECIAL FEATURE CODES
Modern telephone keypad contains "*" and "#"
Telephone numbers are sometimes prefixed with special services, such
as vertical service codes , that contain signaling events other than
numbers, most notably the star (*) and the number sign (#). Vertical
service codes enable or disable special telephony services either on a
per-call basis, or for the station or telephone line until changed.
The use of the number sign is most frequently used as a marker signal
to indicate the end of digit sequences or the end of other procedures;
as a terminator it avoids operational delays when waiting for
expiration of automatic time-out periods.
IN POPULAR CULTURE
Australian films and television shows do not employ any recurring
format for fictional telephone numbers; any number quoted in such
media may be used by a real subscriber. The 555 code is used in the
Balmain area of Sydney and the suburbs of
Melbourne . Although in many
areas being a prefix of 55 plus the thousand digit of 5 (e.g. 55
5XXX), would be valid, the numbering system was changed so that 555
became 9555 in Sydney and Melbourne, and in the country, there are 2
new digits ahead of the 55.
However, elsewhere, as in the United States, fictitious telephone
numbers are often used in films and on television to avoid
disturbances by calls from viewers. For example, The
United States 555
(KLondike-5) exchange code was never assigned (with limited exceptions
such as 555-1212 for directory assistance ). Therefore, American films
and TV shows have used 555-xxxx numbers, in order to prevent a number
used in such a work from being called.
Bruce Almighty (2003) originally featured a number that did
not have the 555 prefix. In the cinematic release, God (Morgan Freeman
) leaves 776-2323 on a pager for Bruce Nolan (
Jim Carrey ) to call if
he needed God's help. The DVD changes this to a 555 number . According
Universal Studios , which produced the movie, the number it used
was picked because it did not exist in
Buffalo, New York
Buffalo, New York , where the
movie was set. However, the number did exist in other cities,
resulting in customers' having that number receiving random calls from
people asking for God. While some played along with the gag, others
found the calls aggravating.
The number in the
Glenn Miller Orchestra
Glenn Miller Orchestra 's hit song "Pennsylvania
6-5000 " (1940) is the number of the
Hotel Pennsylvania in New York
City . The number is now written as 1-212-736-5000. According to the
PEnnsylvania 6-5000 is New York's oldest continually
assigned telephone number and possibly the oldest
continuously-assigned number in the world.
Tommy Tutone 's hit song "
867-5309/Jenny " (1981) led to many
unwanted calls by the public to telephone subscribers who actually
were assigned that number.
Telephone numbers for sale in
Hong Kong . The prices are higher
for desirable numbers.
Telephone numbers by country
List of country calling codes
List of country calling codes
National conventions for writing telephone numbers
Number translation service
* vanity number
Automatic number identification (ANI)
Automatic number announcement circuit (ANAC)
Dialed Number Identification Service (DNIS)
Carrier access code (CAC)/
Carrier identification code (CIC)
* ^ AT&T, Notes on Distance Dialing (1968), Section II, p.1
* ^ A B Brooks, John. Telephone: The First Hundred Years. Harper &
Row, 1967, ISBN 0-06-010540-2 : p. 74 , citing "Events in Telephone
* ^ A B Bellcore SR-2275 Bellcore Notes on the Network, Issue 3,
Section 3 page 15. (December 1997)
* ^ A B NANPA definition of vertical service codes
* ^ Fischer, Claude S. America Calling: A Social History of the
Telephone to 1940. Berkeley: University of California Press, 1992.
* ^ PhoneNumberGuy.
* ^ International Correspondence Schools (1916). Subscribers\'
Station Equipment. International Library of Technology. Internal
Textbook Company. p. 20. Retrieved 2008-05-27.
* ^ A B Cuccia, Mark. "CODE 555 AND THE MOVIES". Telecom Heritage
Telephone Collectors Society Inc.
* ^ Vries, Lloyd (27 May 2003). "\'Almighty\' Phone Mess". CBS News
* ^ \'Bruce Almighty\' delivers wrong number. People Online.
Retrieved on 2009-05-04.
* ^ Carlson Jen (2 July 2014). "The Oldest Phone Number In NYC".
* ^ "Old New York: Historical Attractions".
Hotel Pennsylvania . 23
January 2014. New York.
* ^ Mikkelson, Barbara (9 July 2014). "867-5309 / Jenny".