A Swiss rotary telephone dial from the 1970s, showing the telephone's number 94 29 68 along with various local emergency services. A telephone number serves as an address for switching using a system of destination code routing. Telephone numbers are entered or dialed by a on the originating telephone set, which transmits the sequence of digits in the process of signaling to a. Telephone numbers are assigned within the framework of a national or regional to subscribers by telephone service operators, which may be commercial entities, state-controlled administrations, or other industry associations. Telephone numbers were first used in 1879 inwhen they replaced the request for subscriber names by callers connecting to the. Over the course oftelephone numbers had various lengths and formats, us phone number even included most letters of the alphabet in leading positions when were in us phone number use until the 1960s. Telephone numbers are often dialed in conjunction with other signaling code sequences, such asto invoke special telephone service features. This section does not any. Unsourced material may be challenged and. November 2015 When telephone numbers were first used they were very short, from one to three digits, and were communicated orally to a when initiating a call. As telephone systems have grown and interconnected to encompass worldwide communication, telephone numbers have become longer. In addition tothey have been used to access other devices, such as, and. Withmodems and pagers falling out of use in favor of all-digital always-connected andtelephone numbers are now often used by data-only devices, such as some,andon which it is not even possible to make or accept a. The number contains the information necessary to identify uniquely the intended endpoint for the. Each such endpoint must have a unique number within the. 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 us phone number most often used. Some special services have their own short numbers e. The dialing plan in some areas permits dialing numbers in the local calling area without using 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 us phone number digits for the line number. If the area has no area code overlays or if the provider allows it, seven-digit dialing may be permissible for calls within the area, but some areas have implemented mandatory. Other special phone numbers are used for high-capacity numbers with severaltypically a to a where dozens or even hundreds of callers may be trying to call in at once, such as for a contest. For each largeall of these lines will share the same prefix such as -741- xxxx in Atlanta and -550- xxxx inthe last digits typically corresponding to the station's, or. In the international telephone network, the format of telephone numbers is standardized by recommendation. This code specifies that the entire number should be 15 digits or shorter, and begin with a. For most countries, this is followed by an area code or us phone number code and the subscriber number, which might consist of the code for a particular. When calling an international number from a landline phone, the + must be replaced with the chosen by the country the call is being made from. In the United States, each state's regulates, as does the. In Canada, which shares the same country code with the U. Number portability usually has geographic limitations, such as an only being able to port to within the same. Mobile carriers may have much larger market areas, and can assign or accept numbers from any area within the region. In many telephone administrations, cell phone telephone numbers are in organized in prefix ranges distinct from land line service, which simplifieseven between carriers. Within most North American rate centres, local wireline calls are free, while calls to all but a few nearby rate centres are considered and incur toll fees. History United States See also: In the late 1870s, the interests started utilizing their with a rental scheme, in which they would rent their instruments to individual users us phone number would contract with other suppliers to connect them; for example from home to office to factory. Such an office was staffed by an 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 us phone number early part of 1880 saw the first use of telephone numbers at. During an epidemic of measles, the physician, Dr. 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. In rural areas with connected tothe local phone number consisted of the line number plus the ringing pattern of the subscriber. 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 and subscribers on one line. In the most areas oftelephone us phone number 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 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. 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. Alphanumeric telephone numbers 2008 us phone number shows a hairdressing shop in 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 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. This process was complete by the early 1960s. United Kingdom Main article: In theletters 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 letter Q. Until then, only the 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 us phone number of lettered dials. The need us phone number dials with letters ceased with the conversion to all-digit numbering in 1968. Intercepted number 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. Disconnected numbers are reassigned to new users after the rate of calls to them declines. Outside of North America operator intercept was rare, and in most cases calls to us phone number or disconnected numbers would result in a recorded message or number-unobtainable tone being returned to the caller. 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. Although in many areas being a prefix of 55 plus the thousand digit of 5 e. However, elsewhere, as in the United States, are often used in films and on television to avoid disturbances by calls from viewers. The film 2003 originally featured a number that did not have the 555 prefix. In the cinematic release, God leaves 776-2323 on a pager for Bruce Nolan to call if he needed God's help. According towhich produced the movie, the number it used was picked because it did not exist inwhere 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 is now written as 1-212-736-5000. Us phone number to the hotel's website, is New York's oldest continually assigned telephone number and possibly the oldest continuously-assigned number in the world. Telephone: The First Hundred Years. America Calling: A Social History of the Telephone to 1940. Berkeley: University of California Press, 1992. Australian Telephone Collectors Society Inc. Archived from on 13 June 2004.
