Telephone exchange nameswikipedia
A telephone exchange name or central office name was a distinguishing and memorable name assigned to a central office.
telephone exchange namescentral office nametelephone exchangetelephone exchange namenamedDOMinionBUtterfield 8named exchangesname given to the exchangesOLiver 2

Telephone number

telephone numberphone numbertelephone numbers
Each central office served a maximum of 10,000 subscriber lines identified by the last four digits of the telephone number.
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.

All-figure dialling

all-figure diallingall figure dialling01609
Similar developments followed around the world, such as the British all-figure dialling.
All-figure dialling was a telephone numbering plan introduced in the United Kingdom starting in 1966 that replaced the traditional system of using initial letters of telephone exchange names as the first part of a telephone number.

List of original NANP area codes

original area codesoriginal 86 area codesoriginal numbering plan areas
In the 1940s, the Bell System developed the North American Numbering Plan, a system of initially 86 allocated area codes which were used at first only by switchboard operators to route trunk calls between plan areas.
This included a three-digit central office prefix, dialed as the first two letters of the local central office name and one digit, and the four-digit subscriber station number.

PEnnsylvania 6-5000

telephone number
For example, under this system, a well-known number in New York City was listed as PEnnsylvania 6-5000. At least four popular songs use old telephone exchanges in their names: "PEnnsylvania 6-5000" (PE 6-5000), recorded by Glenn Miller (the inspiration for that song, the Hotel Pennsylvania in New York City, still holds that phone number as +1-212-736-5000); "BEechwood 4-5789", by The Marvelettes; "LOnesome 7-7203 by Hawkshaw Hawkins; and "ECho Valley 2-6809" by The Partridge Family. PEnnsylvania 6-5000 was later spoofed in the Bugs Bunny cartoon Transylvania 6-5000 and the horror/comedy film Transylvania 6-5000.
The named Pennsylvania exchange served the area around Penn Station in New York.

Direct distance dialing

direct distance dialingdirect dialdirect distance dial
Eventually, starting in the late 1940s, all local numbering plans were changed to the 2L-5N system to prepare for nationwide Direct Distance Dialing.
Customers of the ENglewood 3, ENglewood 4 and TEaneck 7 exchanges, who could already dial New York City and area, were able to dial 11 cities across the United States, simply by dialing the three-digit area code and the seven-digit number, which at the time consisted of the first two letters of the central office name and five digits.

Telephone exchange

telephone exchangeexchangescentral office
A telephone exchange name or central office name was a distinguishing and memorable name assigned to a central office.
During this transition period, once numbers were standardized to the 2L-4N or 2L-5N format (two-letter exchange name and either four or five digits), it was possible to dial a number located in a manual exchange and be connected without requesting operator assistance.

All-number calling

all-number calling
In the United States, the demand for telephone service outpaced the scalability of the alphanumeric system and after introduction of area codes for direct-distance dialing, all-number calling became necessary.
All-number calling (ANC) is a telephone numbering plan that was introduced by the Bell System in the United States starting around 1958 to replace the previous system of using a telephone exchange name as the first part of a telephone number.

North American Numbering Plan

Area codeArea codes<span style="white-space:nowrap;">Area code(s)
In the 1940s, the Bell System developed the North American Numbering Plan, a system of initially 86 allocated area codes which were used at first only by switchboard operators to route trunk calls between plan areas.
This was already common practice, because the system of using the initial letters of central office names did not assign letters to digits 1 and 0.

Beechwood 4-5789

At least four popular songs use old telephone exchanges in their names: "PEnnsylvania 6-5000" (PE 6-5000), recorded by Glenn Miller (the inspiration for that song, the Hotel Pennsylvania in New York City, still holds that phone number as +1-212-736-5000); "BEechwood 4-5789", by The Marvelettes; "LOnesome 7-7203 by Hawkshaw Hawkins; and "ECho Valley 2-6809" by The Partridge Family. PEnnsylvania 6-5000 was later spoofed in the Bugs Bunny cartoon Transylvania 6-5000 and the horror/comedy film Transylvania 6-5000.
The song's title is derived from the now-defunct use of telephone exchange names in telephone numbers.

S. I. Hayakawa

S.I. HayakawaHayakawaSamuel Ichiye Hayakawa
In some cities such as San Francisco, opposition was organized; the opposition group in San Francisco was called the Anti Digit Dialing League, of which S. I. Hayakawa was a notable member.
In the early 1960s, he helped organize the Anti Digit Dialing League, a San Francisco group that opposed the introduction of all-digit telephone exchange names.

BUtterfield 8

Butterfield 8Butterfield Eight1960 film
The title of BUtterfield 8, the 1935 John O'Hara novel whose film adaptation won Elizabeth Taylor an Academy Award for Best Actress, refers to the exchange of the characters' telephone numbers (on the Upper East Side of Manhattan).
An insulted Gloria, whose dress is torn, takes Liggett's wife Emily's (Dina Merrill) mink coat to cover herself and scrawls "No Sale" in lipstick on the mirror, but she orders her telephone answering service, BUtterfield 8, to put Liggett through if he calls.

Artie Shaw

Artie ShawArtie Shaw and His OrchestraShaw
Artie Shaw and His Gramercy 5—Artie Shaw named his band the Gramercy Five after his home telephone exchange in Greenwich Village.
He named it Artie Shaw and the Gramercy Five, after his home telephone exchange.

Telephone numbering plan

Area codeCalling codearea codes
In the United States, the demand for telephone service outpaced the scalability of the alphanumeric system and after introduction of area codes for direct-distance dialing, all-number calling became necessary. Several systematic telephone numbering plans existed in various communities, typically evolving over time as the subscriber base outgrew older numbering schemes.

Telephone keypad

telephone keypadkeypadnumeric keypads
Originally, they referred to the leading letters of telephone exchange names.

Hotel Edison

Edison BallroomEdison Hotel
It attempted to mimic the telephone number PEnnsylvania 6-5000 of the Hotel Pennsylvania by using the telephone exchange name CIrcle 6-5000.

555 (telephone number)

555 (telephone number)555555 telephone number
In television shows made or set in the mid-1970s or earlier, "KLondike 5" or "KLamath 5" reflects the old convention for telephone exchange names.

Push-button telephone

push-button telephonepush-button dialingpushbutton telephones
As direct distance dialing expanded to a growing number of communities, local numbers (often four, five or six digits) were extended to standardized seven-digit named exchanges.

Area codes 514 and 438

514 and 438(514) and (438)514
In 1898, exchange names ("Main", "Westmount", "Uptown" or "East") were added before the number.

The Flintstones

FlintstonesFlintstonethe Flintstones
After spending a brief period in development as The Gladstones (GLadstone being a Los Angeles telephone exchange at the time), Hanna-Barbera settled upon The Flintstones, and the idea of the Flintstones having a child from the start was discarded, with Fred and Wilma starting out as a childless couple.

Zenith number

ZenithZenith" X-XXXXWX number
In that era, direct-dial numbers were commonly published with telephone exchange names followed by digits, such as in the telephone number "PEnnsylvania 6-5000".

Butterfield Market

It is named for the old telephone exchange name for the neighborhood, Butterfield 8.

E.161

ITU-T E.161ITU E.161letters assigned to most of the digits
The E.161 layout is primarily based on the layout used on American telephones since the 1930s for telephone exchange names.

Telephone prefix

prefixtelephone prefixdialing prefix
As progress was made, exchanges were connected together, initially connected by the operator by name, and later dialed by users with prefixes such as WHI (for the WHItehall exchange, hence the famous Whitehall 1212 number for Scotland Yard), with letters corresponding to numbers on the dial (WHI was equivalent to # 944), later replaced by the numerical prefixes which remain in use.