Number

Number

Number

North America
North American Numbering Plan
NANPA" redirects here. For other uses, see Nanpa.
This article is about the numbering plan. For a list of area codes under the plan, see List of North American Numbering Plan area codes.
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Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (March 2009). - The - North American Numbering Plan - ( - NANP - ) is an integrated telephone numbering plan of 24 countries and territories: the United States and its territories, Canada, Bermuda, and 16 of the Caribbean countries. The term is also used, by metonymy, to refer to the geographic area in which that plan has been implemented.
The NANP is a standardized system of numbering plan areas (NPA), which have evolved over time into a system of three-digit area codes and seven-digit telephone numbers. Through this plan, telephone calls can be directed to particular regions of the larger NANP public switched telephone network (PSTN), where they are further routed by the local networks.
Contents
Current system
Dialing plans
Charges
History
Calls to Mexico (until 1991)
Expansion of area codes
6.1Splits and overlays
6.2Expansion issues
6.3Decrease in expansion rate
Alphabetic mnemonic system
Cellular services and the NANP numbering scheme
New area codes outside the U.S. and Canada
Fictional telephone numbers
Future expansion of NANP
Special numbers and codes
List of NANPA countries and territories
See also
References
External links
Current system
Developed in 1947, and first implemented in 1951 by AT&T, the NANP set out to simplify and facilitate direct dialing of long distance calls. Area code 201 was the first implemented under the plan.[1 - The NANP initially applied only to the U.S. and Canada, but at the request of the British Colonial Office, it was expanded to Bermuda and the British West Indies (including Trinidad and Tobago), because of their historic telecommunications administration through Canada as parts of the British Empire - and also their continued associations with Canada, especially during the years of the telegraph and the All Red Line system.
Despite the "North American" name of the calling plan, not all North American countries participate in NANP. Mexico, the Central American countries and some Caribbean countries (Cuba, Haiti, and the French and Dutch-speaking Caribbean) are not part of the system. The only Spanish-speaking country in this plan is the Dominican Republic (although Spanish-speaking U.S. commonwealth Puerto Rico is as well). Mexican participation was planned, but implementation stopped after two area codes were put into use (Mexico City and northwestern Mexico); these ended in 1991 when Mexico withdrew from the NANP.
The NANP is administered by the North American Numbering Plan Administration (NANPA).
Current NANP number format can be summed up via the following:
+1- NPA - NXX - xxxx -
Component - Name - Number ranges - Notes
+1 - ITU country calling code - Most often written without the leading ""; generally indicates access to long-distance service within NANP.
NPA - Numbering Plan Area Code - Allowed range of [2-9] for the first digit, [0-8] for the second, and [0-9] for the third digit. - Covers Canada, the United States, parts of the Caribbean Sea, and some Atlantic and Pacific islands. The area code is often enclosed in parentheses.
NXX - Central Office (exchange) code - Allowed ranges [2-9] for the first digit, and [0-9] for both the second and third digits. - Often considered part of a subscriber number. The three digit Central Office codes are assigned to a specific CO serving its customers, but may be physically dispersed by redirection, or forwarding to mobile operators and other services.
xxxx - Subscriber Number - [0-9] for of the four digits. - This unique four digit number is the subscriber number or station code.. - For example:
(234) 235 5678 is valid
(123) 234 5678 is invalid, because NPA cannot begin with a "1"
The country calling code for the NANP is +1. In international format, an NANP number should be listed thus: +1 301 555 0100 (example using the Maryland area code). "1" is also the code often used to make direct-dialed long-distance calls within the NANP.
Each three-digit area code may contain up to 7,919,900 unique phone numbers:
NXX may begin only with the digits [2-9], providing a base of 8 million numbers: ( 8 x 100 x 10000 ) .
However, the last two digits of NXX cannot both be 1, to avoid confusion with the N11 codes (subtract 80,000).
Despite the widespread usage of NXX "555" for fictional telephone numbers — see 555 (telephone number) — today, the only such numbers specifically reserved for fictional use are "555-0100" through "555-0199", with the remaining "555" numbers released for actual assignment (subtract 100).
Dialing plans
Dialing plans vary from place to place depending on whether an area has overlays (multiple area codes serving the same area) and whether the jurisdiction requires toll alerting (a leading 1 for toll calls). The NANPA's web site includes dialing plan information in its information on individual area codes.
The standard dialing plan in most cases are as follows:
- Local within area code - Local outside area code - Toll within area code - Toll outside area code
Single code area, with toll alerting - 7D - 7D or 10D - 1+10D - 1+10D
Single code area, without toll alerting - 7D - 1+10D - 7D or 1+10D - 1+10D
Overlaid area, with toll alerting - 10D - 10D - 1+10D - 1+10D
Overlaid area, without toll alerting - 10D or 1+10D - 1+10D - 10D or 1+10D - 1+10D. - Most areas allow permissive dialing of 10D or 1+10D even for calls that could be dialed as 7D. The number of digits dialed is unrelated to whether a call is local or toll when there is no toll alerting. Allowing 7D local dialing across an area code boundary (which is uncommon today and only possible with toll alerting) requires NXX protection on the other side to avoid dialing conflicts.
Most areas permit local calls to be dialed as 1+10D except for Texas, Georgia, and some jurisdictions in Canada which require that callers know which numbers are local and which are toll, dialing 10D for all local calls and 1+10D for all toll calls.
In almost all cases, operator-assisted calls require dialing 0+10D.
Charges
Despite the similar dialing format, calls between different countries and territories that use the NANP are not necessarily charged as domestic. Calls between the US and Canada are treated as international, although typically charged at lower rates than calls to other countries. Calls to other destinations in the NANP area can be high; for example, it generally costs more to call Bermuda from the US than it does to call the UK or Japan, even though the dialing format is the same as the domestic format. Similarly, calls from Bermuda to US numbers, (including toll-free 1- 800), incur high international rates. This was because many of the island nations at the time implemented a plan of subsidizing the cost of local phone services by directly charging heavier pricing levies on the international Long Distance services.
Because of these higher fees, a handful of scams had taken advantage of customers' unfamiliarity with pricing structure to call the legacy regional 809 area code. Some scams lured customers from the U.S. and Canada into placing expensive calls to the Caribbean, by representing the area code 809 as a regular domestic, low-cost, or toll-free call. These scams are currently on the decline, with many of the Cable and Wireless service monopolies being opened up to competition, hence bringing rates down. Additionally, many Caribbean territories have implemented local government agencies to regulate telecommunications rates of providers.[2 -
History
In order to facilitate direct dialing calls, the NANP was created and instituted in 1947 by AT&T, also known as the Bell System, the U.S. telephone semi- monopoly. At first, the codes were used only by long-distance operators; the first customer-dialed calls using area codes did not occur until November 10, 1951, when the first directly-dialed call was made from Englewood, New Jersey to Alameda, California.[4 - Direct dialing was gradually instituted throughout the country, and by the mid-1960s, it was commonplace in most larger cities.
Originally there were only 86 codes, with the biggest population areas getting the numbers that took the shortest time to dial on rotary telephones.[5 - That is why New York City was given 212, Los Angeles 213, Chicago 312, Philadelphia 215 and St. Louis received 314, while four areas received the n-maximum number of 21 clicks: South Dakota (605), North Carolina (704), South Carolina (803), and Nova Scotia/Prince Edward Island in the Canadian Maritimes (902). Additionally, in the original plan a middle digit of - 0 - indicated the area code covered an entire state/province, while area codes with a middle digit of - 1 - were assigned to jurisdictions that were divided into multiple area codes. ]
At first, area codes were all in the form N-Y-X, where N is any number 2-9, Y is 0 or 1, and X is any number 1-9 (if Y is 0) or any number 2-9 (if Y is 1). The restriction on N saves 0 for calling the operator, and 1 for signaling a long-distance call. The restriction on the second digit, limiting it to 0 or 1, was designed to help telephone equipment recognize the difference between a three-digit "area code" (with 0 or 1 as the second digit) and the three-digit "exchange" prefix (which had avoided 0 or 1 for the second digit, because of restrictions in existing switching equipment). For example, when a caller dialed "202-555-1212", the switching equipment would recognize that "202" was an area code because of the middle 0, and route the call appropriately. If a caller were to dial 345-6789, the 4 would be recognized as a long-distance call within the area code and routed as such, without waiting to see or guessing at how many digits the caller meant to enter.
In the late 1980s and early 1990s, NANPA (then still part of Bellcore, which is now Telcordia Technologies) began to urge and later require all long-distance calls within each area to be prefixed with the digit 1 to distinguish them from local calls, so that badly-needed prefixes with 0 or 1 in the middle could be assigned to local telephone exchanges. Also, since it had nearly run out of area codes using the above formula, it allowed the assignment of area codes using the form N-1-0, such as 210 in the San Antonio, Texas, area and 410 in eastern Maryland. Therefore, someone calling from San Jose to Los Angeles before the change would have dialed 213-555-1234 and after the change 1-213-555-1234, which then allowed 213 to be used as an exchange prefix in the San Jose area.
Calls to Mexico (until 1991)
Until 1991, calls to some areas of Mexico from the United States and Canada were made using the North American Numbering Plan area codes. For example, to call a number in northwest Mexico and Mexico City before 1991:
1 905 - Nxx xxxx (Mexico City
1 706 - Nxx xxxx (northwest Mexico) (prior to 1980, the code was 903, rather than 706
From 1991, Mexican participation in the NANP was discontinued in favor of the general international format, and then the Area Code 905 was assigned to Greater Toronto Area in Canada outside of Toronto (which retained Area Code 416), and Area Code 706 was reassigned to northern Georgia, surrounding the Atlanta region which retained 404:
+52 5 - xxx xx xx (Mexico City; now - +52 55 - xx xx xx xx (eight-digit local number, land line)
+52 5 - xxx xx xx (Mexico City; now - +52 1 55 - xx xx xx xx (eight-digit local number, cellular phone)
+52 6 - xxx xx xx (northwestern Mexico; now - +52 6xx - xxx xx xx, land line
+52 6 - xxx xx xx (northwestern Mexico; now - +52 1 6xx - xxx xx xx, cellular phones
Expansion of area codes
Canada and the United States have experienced rapid growth in the number of area codes, particularly in the 1990s and early 2000s. There are two main reasons for this. First, there is the increasing demand for telephone services (particularly resulting from widescale adoption of fax, modem, and mobile phone communications).
The second and more important reason is the telecom deregulation of local telephone service in the US beginning in the early to mid-1990s. At that time, the Federal Communications Commission began allowing telecommunication companies to compete with the incumbent local exchange carrier (usually by forcing the existing monopoly service provider to lease infrastructure to other local providers who then resold the service to consumers). However, because of the original design of the numbering plan and telephone switching network that assumed only a single provider, number allocations had to be made in 10,000-number blocks.
Thus, anytime a new local service provider entered a certain market it would be allocated 10,000 numbers by default, even if the provider only obtained a few (if any) customers. As more companies began requesting numbering allocations, this caused many area codes to begin exhausting their supply of available numbers (code "in jeopardy" in telecom jargon), and additional area codes were needed. In reality, many of the new telecom ventures were not successful; while the number of area codes started increasing rapidly, this did not necessarily translate to a much larger number of actual telephone subscribers as large blocks of numbers lay unassigned to any "real" subscribers because of the 10,000-number block allocation requirement. When these telecom ventures are merged or bought or liquidate, their blocks go to the successor, or go unused. No regulatory mechanism exists to reclaim and reassign these underutilized blocks.
In general, area codes were added either as "splits" (in which an area code was divided into two or more regions, one retaining the older area code and the other area(s) receiving a new code), or "overlays", in which multiple area codes are assigned to the same geographical area. Subtle variations of these techniques have been used as well, such as "dedicated overlays" [in which the new overlaid area code was reserved for a particular type of service, such as cellular phones and pagers (the only true example of this was area code 917 in New York City)] and "concentrated overlays", in which some of the area retained a single area code, while the rest of the region received an overlay code.
After the remaining valid area codes were used up by expansion, in 1995 the rapid increase in the need for more area codes (both splits and overlays) forced NANPA to allow the digits 2 through 8 to be used as a middle digit in new area code assignments, with 9 being reserved as a "last resort" for potential future expansion. At the same time, local exchanges were allowed to use 1 or 0 as a middle digit. The first area codes without a 1 or 0 as the middle digit were area code 334 in Alabama and area code 360 in Washington, which both began service on January 15, 1995. Area codes, or "numbering plan areas" ending in double digits, such as toll-free 800, 888, 877, and 866, personal 700 numbers, and high-toll 900 numbers, are reserved as easily-recognizable codes (ERCs) and are not issued to actual geographic areas. (Nevada was denied - 777 - for this reason; it received - 775 - instead when most of Nevada split from 702, which continues to serve the Las Vegas area.
Splits and overlays
By 1995, many cities in the United States and Canada had more than one area code, either through splitting the city into different areas (splits) or having more than one area code for the same geographical area (overlays). For example, in Manhattan, subscribers' numbers had the NPA code 212, but two additional codes—first 917 (which initially was exclusively for cellular phones and pagers until that idea was struck down in a Federal court), then 646—were also introduced. This means that the area code must be dialed, even for local calls. In other areas, 10-digit or 11-digit dialing is now required for all local calls. The transition to 10-digit dialing typically starts with a permissive dialing phase in which both 7-digit and 10-digit dialing is optional. During this period, the transition is heavily publicized. After a period of several months, the mandatory dialing phase is introduced, in which 7-digit dialing no longer works. Atlanta was the first US city to have mandatory 10-digit dialing throughout its metropolitan area, roughly coinciding with the 1996 Summer Olympics held there. Atlanta was used as the test case not only because of its size, but also because it enjoyed the world's largest fiber optic network at the time (five times that of New York then), and it was home to BellSouth (now part of AT&T), then the Southeastern Regional Bell Operating Company. ]
7-digit dialing: - Nxx xxxx - (NPA code not required
10-digit dialing: - NPA Nxx xxxx -
11-digit dialing: - 1 NPA Nxx xxxx -
The overlap between area codes and exchange prefixes has occasionally produced some confusion because the three digits can be the same for both. Nashua, New Hampshire, for example, has a local exchange that begins with (603) 888, which is also an area code for toll-free calls. If somebody in Nashua means to call 1-888-555-1212 but forgets the initial "1," he or she will actually dial the local number 1-603-888-5551. This, however, is generally not a problem in major metropolitan areas with overlapping area codes, which were mandated by the FCC to dial all ten digits for all local calls so as not to give new numbers or telecommunications providers a "disadvantage."
Expansion issues
Depending on the techniques used for area code expansion, the effect on telephone users varies. In areas in which overlays were used, this generally avoids the need for converting telephone numbers, so existing directories, business records, letterheads, business cards, advertising, and "speed-dialing" settings can retain the same phone numbers, while the overlay is used for new number allocations. The primary impact on telephone users is the necessity of remembering and dialing 10- or 11-digit numbers when only 7-digit dialing was previously permissible.
The use of a splitting instead of an overlay generally avoids the requirement for mandatory area-code dialing, but at the expense of having to convert some of the numbers to the new Area Code. In addition to the requirements of updating records and directories to accommodate the new numbers, for efficient conversion this requires a period of "permissive dialing" in which both the new and old Area Codes of the splitting are allowed to work. Also, in many splittings there were significant technical issues involved, especially when the Area Code splittings occurred over boundaries other than phone network divisions.
As an extreme example of an area code splitting gone somewhat awry, in 1998 the Minneapolis – Saint Paul Twin Cities, which until that point used just the 612 area code, split into the 612 and 651 Area Codes, with St. Paul and the eastern metropolitan area receiving the new 651 Area Code. However, the Minnesota Public Utilities Commission mandated that the boundary of this splitting exactly follow municipal boundaries (which were distinctly different from telephone exchange boundaries), and that all subscribers keep their 7-digit numbers. These two goals were directly at odds with the reason for the area code splitting (to generate additional phone numbers), and there were more than 40 exchanges whose prefix territory straddled town boundaries along the Area Code splitting. The result was prefixes duplicated in both Area Codes, which counteracted much of the benefit of the splitting, with only 200 of 700 prefixes in the 612 Area moving entirely to the 651 Area. As a result, in less than two years the 612 Area Code again exhausted its supply of phone numbers, and it underwent another three-way split in the year 2000 - creating the new 763 and 952 Area Codes. Again, the split followed political boundaries rather than rate center boundaries, resulting in additional split prefixes, and in a few cases resulted in numbers initially moved to the 651 Area Code being moved again to the 763 Area Code in less than two years.
Decrease in expansion rate
Recognizing that the major cause in the proliferation of area codes was due to the telecom deregulation act and the 10,000 number block assignment, the FCC instructed NANPA (by then administered by NeuStar) to look for a solution to alleviate the numbering shortage. As a result a new program called "number pooling" was piloted in 2001 which allowed allocating numbers in 1,000-number blocks rather than 10,000 numbers. Because of the design of the switched telephone network, this was a considerable technical challenge and was carried out together with another technically-challenging program, local number portability. Since then the program has been rolled out to most parts of the United States and together with aggressive reclamation of unused number blocks from telecom providers, the need for additional area codes has been reduced, so much so that the implementation of large numbers of previously designated area splits and overlays has been postponed indefinitely.
Alphabetic mnemonic system
Another oddity of NANP telephone numbering is the use of alphabetic dialing. On most US and Canadian telephones, three letters appear on each number button from 2 through 9 (as standardized much later by ISO 9995-8 and, in Europe, E.161). This accommodates 24 letters. Historically, the letters Q and Z were omitted, though on some modern telephones, they are added, so that the alphabet is apportioned as follows:
 2 = ABC
 3 = DEF
 4 = GHI
 5 = JKL
 6 = MNO
 7 = PRS or PQRS
 8 = TUV
 9 = WXY or WYZ or WXYZ
. - No letters are allocated to the 1 or 0 keys (although some corporate voicemail systems are set up to count Q and Z as 1, and some old telephones assigned the Z to the digit 0).
Originally, this scheme was meant as a mnemonic device for telephone number prefixes. When telephone numbers in the US were standardized in the mid-20th century, they were made seven digits long, including a two-digit prefix, the latter expressed as letters rather than numbers. (Before World War II, a few localities used three letters and four numbers; in most cities with customer dialing, phone numbers had only six digits — two letters followed by four numbers.) The prefix was a name, and the first two or three letters (usually shown in capitals) of the name were dialed. Later, the third letter (where previously used) was replaced by a number, or an extra number was added; this generally happened after World War II, although New York City did this in 1930. Thus, the famous Glenn Miller tune "PEnnsylvania 6-5000" refers to a telephone number 736-5000, the number of the Hotel Pennsylvania, which still bears the same number today. Similarly, the classic Elizabeth Taylor film "BUtterfield 8" refers to the section of New York City where the film is set, where the telephone prefixes include 288 (on the East Side of Manhattan between roughly 64th and 86th Streets). This is why, in some works of fiction, phone numbers will begin with "KLondike 5" or "KLamath 5", which translates to 555, a mostly unused and reserved exchange. This practice continues in film and television to this day, even though the prefix system has long been unused. ]
Today this system has been abandoned (it was phased out starting in the early 1960s, though it persisted in some places as late as the mid-1970s, and was included in Bell of Pennsylvania directories until 1983, and there is a construction company in Philadelphia that still has alphabetic exchanges on some of their dump trucks as of 2010), but alphabetic dialing remains as a commercial mnemonic gimmick, particularly when combined with toll-free numbers. For example, one can dial 1-800-FLOWERS to send flowers to someone, or 1-800 DENTIST to find a local dentist. Sometimes, longer phonewords are used - for example one might be invited to give money to a public radio station by dialing 1-866-KPBS-GIVE. The "number" is 8 digits long, but only the first seven need be dialed. If an eighth (or more) digit is dialed, the switching system will ignore it. Mobile users may need to manually drop any numbers past the seventh digit as some mobile switching systems will not automatically ignore them, resulting in a failed call. In addition to commercial uses, alphabetic dialing has influenced, in rare cases, the choice of regional area codes in the United States. For example, when East Tennessee was split into two area codes in 1999, the region surrounding Knoxville received a new code; the code 865 was chosen to represent the word "VOL"—short for "Volunteers", the nickname of athletic teams at the University of Tennessee. Likewise, when the 606 area code of central and eastern Kentucky was split, Lexington, the region's largest city, adopted the new code 859 (which spells UKY) in honor of the University of Kentucky. The Miami area originally had the 305 area code, but then 786 was added because of the increasing demand for telephone numbers. 786 spells out SUN in honor of Florida being the Sunshine State. 352 is used around Gainesville, Florida, north of Tampa and northwest of Orlando and spells FLA again as a nod to the state. The area around Cape Canaveral, Florida, was split from area code 407 and became area code 321. This represented the launch of a rocket, specifically 3-2-1-Blastoff! The State of Nevada has previously attempted to obtain area code 777 (lucky 7's), but was unable to secure it.[6 - When the Dayton, Ohio area split from the Cincinnati, Ohio Area code 513, literature promoting the new area code 937 took advantage of the fact that the numbers spelled "YES". When the three Canadian northern territories were given their own area code, they were assigned 867, which spells "TOP", reflecting the area's position at the "top" of the world.
See Telephone numbers
Cellular services and the NANP numbering scheme
A difference between the NANP system and other plans is that apart from area code 600 in Canada, no separate, non-geographical area codes have been created for cellular phones, as is the case in most European and Asian countries, where mobile services are assigned their own prefixes. This means that most North American mobile phones are assigned the same locality-specific codes as landlines, and calls to them are billed at the same rate. Consequently, the caller-pays pricing model adopted in other countries, in which calls to cellular phones are charged at a higher nationwide rate, but receiving calls is free, could not be used. Instead, North American cellular telephone users are also generally charged to receive calls as well (subscriber pays). In the past, this discouraged mobile users from using the phones or giving out the number. However, robust price competition among carriers has led to dramatic cuts in the average price per minute for contract customers (for both inbound and outbound calls), which can compare favorably to those in caller-pays countries. Most users select bundle pricing plans that include all the minutes they expect to use in a month. Many carriers also offer free calling between mobile phones on the carrier's network, and some also offer free calling to a list of user-selected phone numbers (which can include both cell phones and landlines).
Some industry observers have blamed user pays as one of the main factors in the relatively low mobile phone penetration rate in the United States compared to that of Europe. In the wireless-subscriber-pays model the convenience of the mobility is charged to the subscriber. Callers from outside the local-calling region of the assigned number are, however, forced to pay for a long-distance call, although domestic long distance rates are generally lower than the rates caller-pays systems charge. Conversely, an advantage of caller-pays is the relative absence of telemarketing and nuisance calls to mobile numbers. The integrated numbering plan also enables local number portability between fixed and wireless services within a region, allowing users to switch to mobile service while keeping their phone number, which is not a common option in caller-pays systems.
The initial plan for overlays did allow for providing separate area codes for use by mobile phones, faxes, pagers, etc., although these were still assigned to a specific geographical area, rather than the nationwide mobile area codes common to most other countries, and were charged at the same rate as other area codes. Initially, the new 917 area code for New York City was specifically assigned for this purpose within the 5 boroughs; however, a Federal court struck this down and banned the use of an area code for a specific telephony purpose. ] Since mobile telephony is expanding faster than landline, new area codes typically have a disproportionately large fraction of mobile numbers, although landline and other services rapidly follow and local network portability can blur these distinctions.
The experience of Hurricane Katrina and similar events revealed a possible disadvantage of the methods employed in the geographic assignment of cellular numbers. Many mobile phone users could not be reached, their phones rendered inoperable, even when they were far from the stricken areas, because the routing of calls to their phones depended on equipment in the affected area.
Another related issue for services like mobile telephony is the scarcity of telephone numbers. In contrast to other countries, where mobile and other special-number operators enjoy wide leeway to generate large numbers of telephone numbers, this is not an option in the NANP, with its geographical area codes with a fixed number of digits.
New area codes outside the U.S. and Canada
Prior to 1995, all other NANP countries and territories outside the fifty United States and Canada, including Puerto Rico and the U.S. Virgin Islands, shared the NPA code 809, but they are now able to have separate codes. Code (809) is now only used by the Dominican Republic. In 1997 the United States Pacific Territories of the Northern Mariana Islands and Guam became part of the NANP, as did American Samoa in October 2004. The Dutch possession of Saint Maarten was originally scheduled to join the NANP on May 31, 2010, but the changeover has been postponed to a yet-to-be determined future date.
Bermuda - :
Until 1995: - +1 809 29 - x xxxx
After 1995: - +1 441 - (xxx) xxxx
Puerto Rico - :
Until 1996: - +1 809 xx - x xxxx
1996-2001: - +1 787 - xxx xxxx
After 2001: - +1 787 - xxx xxxx - or - - +1 939 - xxx xxxx (overlay for entire island
US Virgin Islands - :
Until 1997: - +1 809 xx - x xxxx
After 1997: - +1 340 - xxx xxxx
Northern Marianas - :
Until 1997: - +670 - xxx xxxx
After 1997: - +1 670 - xxx xxxx
Guam - :
Until 1997: - +671 - xxx xxxx
After 1997: - +1 671 - xxx xxxx
American Samoa - :
Until October 1, 2004: - +684 - xxx xxxx
After October 2, 2004: - +1 684 - xxx xxxx
Saint Maarten - :
Currently: - +599 5 - xx xxxx
After joining NANP: - +1 721 - xxx xxxx (date to be determined
See also:Split from the 809 Area code
Fictional telephone numbers
In American television shows and films, - 555 - (or, in older movies and shows, - KL - ondike - 5 - or - KL - amath - 5 - ) is used as the first three digits of fictional telephone numbers, so if anyone is tempted to telephone a number seen on screen, it does not cause a nuisance to any actual person.
There are occasions, however, when a non-555 is used in real-life context, with varying intents and consequences. A classic example of such is the 1982 song "867-5309/Jenny" by Tommy Tutone, which is still the cause of a large number of nuisance calls. Similarly, the song "Diary" by Alicia Keys says to call "489-4608 and I'll be here." It was intended to be called only by people in New York to get her voicemail. At the time that it was recorded in the late 1970s, the B-52's song "6060-842" could not result in a nuisance call, because telephone prefixes could not employ zero as the second digit. Since then, however, the rules governing prefix morphology have changed, causing 606-0842 to become a valid telephone number. In 2003, the movie Bruce Almighty caused controversy because God contacts Bruce, via pager, using an actual phone number 776-2323. The DVD and television versions changed the display of the pager to 555-0123. Another example was when a version of Madonna: Truth or Dare showed Madonna giving out her actual phone number. The phone number was quickly changed and the scene was cut from the movie shortly afterwards. In movies that took place in New York City in the 1940s to the 1960s, numbers like "PLaza 3-9970", "BOwling green 3-9970" or "PLaza 3-5598" were used. At that time, the Public Switched Telephone Network in New York City utilized mainly mechanical switches such as Panel and #1 crossbar and those were "test numbers" that always rang to a busy signal.
Similarly, not all numbers beginning with "555" are fictional. For example, 555-1212 is the number for directory assistance in many places. In many, but not all areas, dialing "555" numbers other than 555-1212 will actually get you to directory assistance as well. In fact, only 555-0100 through 555-0199 are now reserved for fictional use, with the other numbers having been released for assignment. Since "1xx" exchanges are generally not assigned, some movies have started to use fictional telephone numbers starting with "1", giving someone a "telephone number" of 167-1402 in one film,which? ] for example.
Future expansion of NANP
The North American Numbering Plan Administration (NANPA) is now overseen by NeuStar, which will probably face the task of adding one or two digits to each number, likely sometime after 2038[7 - . During that time, all public and private phone systems within the NANP area will have to be upgraded and reprogrammed (or even replaced) to recognize the new dialing rules.
One plan being considered adds a 1 or 0 either to the beginning or end of the area code, or the beginning of the local 7-digit number (or both), which will require mandatory 11-digit dialing (even for local calls), between any two NANP numbers, well before the transition period. In another proposal, existing codes would be changed to "n9xx" (e.g. San Francisco's 415 would become - 4915 - ); once that conversion is complete, the new second digit would be opened for a new range. (Compare PhONE Day in the United Kingdom, which added a "1" to the beginning of area codes in preparation for later using other digits, such as "2", for new area codes.) Other proposals include reallocating blocks of numbers assigned to smaller long distance carriers or unused reserved services.
NANPA previously coordinated an expansion of long-distance carrier access ("dial-around") codes from five digits (such as 10-321) to seven (10-10-321), in 1998. Vertical service codes, such as *69 (callback) and *70 (suspend call waiting), have been designed to allow the use of both two- and three-digit codes.
Special numbers and codes
Some common special numbers in the North American system:
0 - Operator assistance
00 - Long-distance operator assistance
011 - International Access Code. (For all destinations outside the NANP
01 - International Access Code using operator assistance. (For all destinations outside the NANP
10x xxxx - Used to select use of an alternative long-distance carrier
211 - Community information or social services (In some cities), formerly payphone refund line (and prior to that, used to access "long distance" operators in some cities
311 - City government or non-emergency police matters such as noise complaints, suspicious people, minor injuries and non-working streetlights and parking meters, etc. (In some cities
411 - Local telephone directory service (Some telephone companies provide national directory assistance
511 - Traffic, road, and tourist information or reads back the number you are calling from (i.e. drop line ID) (In some cities and states
611 - Telephone line repair service (Some telephone companies use this instead of 4104 or 811). Also used by mobile telephone companies to reach customer service
711 - Relay service for customers with hearing or speech disabilities
811 - "Dig safe" underground pipe safety line in the United States, non-urgent telehealth services in Canada, formerly telephone company business office, mainly to encourage people not to hit telephone or power lines when they dig.
911 - Emergency dispatcher for fire department, ambulance, police etc.
830 or 958 or 9580 or 998 - Returns the number on the line via a recorded voice (in some areas
(Area Code) + 555-1212 - Non-local directory service
There are also special codes, such as:
*51 - A history of unanswered calls on a telephone number, useful for those who are not Caller ID subscribers.
*57 - and - 1157 - (per-use fee.) Used to "trace" harassing, threatening, abusive, obscene, etc. phone calls, and keep results of trace at phone company.
*66 - and - 1166 - To keep retrying a busy-line (see also Called-party camp-on
*67 - and - 1167 - Caller ID Block
*69 - and - 1169 - Call Return caller may press '1' to return call after hearing number
*70 - and - 1170 - Cancel call waiting on a call-by-call basis
*71 - and - 1171 - Three way calling, which lets a person talk to people in two different locations at the same time.
*74 - and - 1174 - Speed dialing, which allows someone to quickly dial any of eight frequently called numbers using a one-digit code, from any phone on their line. *75 allows a total of 30 speed-call numbers.
*82 - and - 1182 - Releases Caller ID block on a call-by-call basis
Note - : The four digit numbers do not work in some areas. The codes prefixed with the "*" symbol are intended for use on Touch-Tone telephones, whereas the four-digit numbers prefixed 11xx are intended for use on older rotary dial telephones, where the Touch-Tone - * - symbol is not available.
Not all NANPA countries use the same codes. For example, the emergency telephone number is not always 911: Trinidad and Tobago and Dominica uses 999, as in the United Kingdom. The country of Barbados uses 211 for police force, 311 for fire, and 511 for ambulance, while Jamaica uses 114 for directory assistance, 119 for police force, and 110 for fire and ambulance services.
Despite its early importance as a share of the worldwide telephone system, few of the NANP's codes, such as 911, have been adopted outside the system. Determining that 911 requires unnecessary rotation time on rotary dial telephones, the European Union has adopted its own standardized number of 112, while countries in Asia and the rest of the world use a variety of other two- or three-digit emergency telephone number combinations. The 112 code is gaining prevalence because of its preprogrammed presence in mobile telephones that conform to the European GSM standard. The European Union and many other countries have chosen the International Telecommunication Union's - 00 - as their international access number instead of 011. The toll-free prefix - 800 - has been widely adopted elsewhere, including as the international toll-free number. It is often preceded by a 0 rather than a 1 in many countries where 0 is the trunk prefix.
List of NANPA countries and territories
 - Antigua and Barbuda
 - Bahamas
 - Barbados
 - Canada
 - Dominica
 - Dominican Republic
 - Grenada
 - Jamaica
 - Saint Kitts and Nevis
 - Saint Lucia
 - Saint Vincent and the Grenadines
 - Sint Maarten (as of May 31, 2010[8 - )
 - Trinidad and Tobago
The following possessions of the United Kingdom :
 - Anguilla
 - Bermuda
 - British Virgin Islands
 - Cayman Islands
 - Montserrat
 - Turks and Caicos Islands
 - United States, including:
 - Guam
 - Northern Mariana Islands
 - Puerto Rico
 - United States Virgin Islands
 - American Samoa
Bell System
List of North American Numbering Plan area codes
List of country calling codes
Original area codes
Vertical service code
References
"Now You Can Call, If Your Calls Don't Work Some Business Lines Aren't Set Up To Call To New Area Codes.", The Virginian-Pilot , November 1, 1995. Accessed June 8, 2007. "When the first area code, 201, was introduced in New Jersey in 1951, phone-numbering experts thought there would be enough codes with a middle digit of ``0 or ``1 to last well into the next century."
The Barbados Fair Trading Commission
The Eastern Caribbean Telecommunications Authority (ECTEL) > Telecom regulations
1951: First Direct-Dial Transcontinental Telephone Call, AT&T. Accessed June 8, 2007. "Nov. 10, 1951: Mayor M. Leslie Downing of Englewood, N.J., picked up a telephone and dialed 10 digits. Eighteen seconds later, he reached Mayor Frank Osborne in Alameda, Calif. The mayors made history as they chatted in the first customer-dialed long-distance call, one that introduced area codes."
Area Code History. Accessed January 4, 2009. "The rationale for this 'low number/high population' scheme was based on the fact that phones had rotary dials in those days. Lower numbers resulted in shorter 'dial pulls' so it was reasoned that the regions with the most people in them should require the least 'work' to call."
Associated Press (1998-02-0). "State approves plan for second area code in northern Nevada". Las Vegas SUN (Greenspun Media Group). http://areacode-info.com/!headline/1998/nv980206a.htm 2007-12-01. "Doug Hescox, area code administrator for Nevada and California, hasn't divulged options for the new code. But he said a "lucky" 777 or a code close to the old 702 - like 701 or 703 - are already reserved or in use elsewhere."
April 2008 NANP Exhaust Analysis
- ^ - "PL-396: Introduction of NPA 721 (Sint Maarten, Netherlands Antilles)". North American Numbering Plan Administration. 2009-10-02. nanpa.com/pdf/PL_396.pdf 2009-10-23.
North American Numbering Plan Administration (NANPA)
Caribbean numbering plan for several islands in the NANP
Map of the original 86 area codes from 1947
Animation of US area codes since 1947
North American Numbering Council
NANP Discussion 2003 Document - "Understanding the North American Numbering Plan"
General Information and Updated References North_American_Numbering_Plan General Information and Updated References
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North America
North American Numbering Plan expansion. - The - North American numbering plan expansion - is a proposed expansion of the North American Numbering Plan to accommodate future needs beyond the current 10-digit limitations used in telephone numbers.
Contents
History
Current industry recommendation
2.1Examples
Other proposals
3.1N9XX, with no change to the remainder of the phone number
3.1.1Examples
3.2N9XX, with a new initial digit
3.2.1Examples
Exhaustion date
See also
References
External links
History
The North American Numbering Plan has been in use since 1947, and has endured that time with only minor changes. So far, unlike many other nations, it has not been necessary to lengthen phone numbers to accommodate expansion. To date, the accommodation of demand has been achieved by adding area codes (NPAs) for relief, either as a split or as an overlay plan.
Although the plan provides for a potential of 6.4 billion telephone numbers, a considerable percentage of these numbers will remain unused when the last available NPA code is assigned, as thousands of numbers will not be in use in exchanges that serve only a small population center, the exchange being served by a single NPA-NXX combination in non-competitive markets (and more combinations in the unlikely event that such a small market has competitors).
As a result, as the supply of unassigned NPA codes dwindles, it will be necessary for telephone carriers in North America to implement expansion beyond the current 10 digit format. Expansion has been a matter of discussion by industry forums for several years, and although a recommendation has been made, that expansion plan format has not been approved by the regulatory authorities (the Federal Communications Commission in the United States and the Canadian Radio-Television and Telecommunications Commission), and the regulators may choose a different expansion plan format.
The industry forum considered dozens of potential options and identified the difficulties with each option.
Current industry recommendation
In the usual phone number jargon, the letter N represents a numeral from 2 through 9, while the letter X represents any numeral. Thus an NXX number may be any from 200 through 999, while XXXX would be 0000 through 9999.
The telephone industry's current recommendation assumes first that mandatory dialing of all ten digits is required to complete telephone numbers, even for a local call, throughout the North American Numbering Plan area, which includes many Caribbean and Pacific territories and nations.
The plan proposes the insertion of two zeroes or two ones between the NPA and the Central Office Code (commonly referred to as an NXX in industry jargon), to produce twelve-digit numbers. The plan further proposes that the United States would use either 00 or 11, while Canada would use the other, in order to allow customers to distinguish countries by use of these digits, which do not appear at the beginning of the 12-digit number.
Under this proposal, the N9X format NPA codes, which are currently reserved from assignment, would be released and be available for normal assignment for code relief and other purposes.

Examples

. - For these examples, we will assume that the new digits will be '00' for the US, and '11' for Canada. With these assumptions, under this plan, the New Jersey telephone number 609-555-0175 would become 6090-0555-0175, and would be dialed as such. Likewise, the Ontario number 613-555-0175 would become 6131-1555-0175.
One advantage is that during the transition period, permissive dialing could be enabled. This means that until everyone has adjusted to the new dialing system, users would still be able dial the shorter, 10 digit numbers. Since currently, the 4th digit (or digit 'D') cannot be 1 or 0, if the telephone system detects 1 or 0 in the 4th position it will process the number as a new 12 digit number, and if it is any digit other than 1 or 0, it can process it as an existing 10 digit number until the transition is complete.
Other proposals
Proposals that utilize the reserved N9X format codes for expansion include the following proposals:
N9XX, with no change to the remainder of the phone number
This proposal would expand numbers to eleven digits overall. A 9 would be inserted as the new second digit of all area codes (e.g. 212 would become 2912, 916 would become 9916). Permissive dialing would be allowed, as exchange equipment, on detecting a 9 as the second digit of the area code, would respond appropriately to expect 11 digits, or 10 in the absence of a 9 in that position.

Examples

. - Under this plan, the New Jersey telephone number 609-555-0175 would become 6909-555-0175.
N9XX, with a new initial digit
With a new initial digit in front of the last seven digits of the phone number, this proposal would expand numbers to twelve digits overall. As with the above plan, a 9 would be inserted as the new second digit of all area codes. The problem would occur with permissive dialing of local calls where the area code is not presently required (areas with no overlay in effect). If the added digit were 3, for example, numbers that already begin with a 3 would present a problem, probably resolved using either a "time-out" if the customer only dials seven digits, or a flash-cut to mandatory eight digit dialing.

Examples

. - Under this plan, the New Jersey telephone number 609-555-0175 could become 6909-3555-0175, although the added '3' in the '3555' could theoretically be any digit.
Exhaustion date
In 2002 the expected date for NANP exhaustion was extended to 2031, making the question less urgent.[1
See also
Neustar
References
FCC report NANP exhaustion, Feb 2003
INC Document
General Information and Updated References North_American_Numbering_Plan_expansion General Information and Updated References
North America
North American Numbering Plan
This category has the following 6 subcategories, out of 6 total.
Area codes in Canada (29 P)
Area codes in the Caribbean (22 P)
Area codes in the United States (1 C, 278 P)
N11 codes (10 P)
Telephone numbers in Canada (2 C, 4 P)
Telephone numbers in the United States (3 C, 44 P)
Pages in category "North American Numbering Plan"
The following 16 pages are in this category, out of 16 total. This list may not reflect recent changes (learn more).
*
North American Numbering Plan
List of original area codes
555 (telephone number)
Area code 721
E
Easily-recognizable code
Enhanced 911
List of North American Numbering Plan area codes
List of area code overlays
N11 code
North American Numbering Plan expansion
Number pooling
Numbering Resource Utilization/Forecast Report
Overlay plan
Seven-digit dialing
Ten-digit dialing
Vertical service code
North American Numbering Plan General Information and Updated References
US Numbering Plan 2024
313 Day: What to know about Detroit's area code Detroit Free Press
Sununu tells state to prepare for day our 603 area code is full Concord Monitor
New Dialing Procedure Becomes Mandatory On October 24, 2021 For All Customers In 82 Area Codes PR Newswire
Are We Running Out of ID Numbers? DISCOVER Magazine