North American numbering plan
As North American Numbering Plan ( NANP; German : North American Numbering Plan ) is a three-digit system is called primaries or ten-digit phone numbers, which especially in the USA , Canada and many Caribbean states is used. All NANP countries have the same common international code +1. Numbering is administered by the North American Numbering Plan Administration (NANPA). A numbering plan specifies the format and structure of numbers in order to be able to calculate distance-dependent telecommunications charges, for example.
Structure and structure
The numbering plan corresponds to recommendation E.164 of the International Telecommunication Union (ITU) and thus the international standard for numbering plans. The 20 areas of the ITU country code with the number 1 for their public telephone network include the territories of the United States, Canada, Bermuda and many Caribbean nations. Guideline E.164 provides the following structure. The sequence of digits is limited to a maximum of 15 digits.
| 15 digits maximum | ||
|---|---|---|
| 1-3 digits | 12-14 digits | |
| (CC) | NDC | SN |
| (Country Code) | National Destination Code (optional) | Subscriber Number |
| ( international phone code ) | optional national area code | Phone number |
| Example for Germany | ||
| (0049) | 030 (for Berlin) | Max. 9-digit telephone number of the participant |
| Example for Canada | ||
| (001) | (NPA) Area Code | Central Office (CO - 3 digits) - four-digit subscriber number |
NANP numbers consist of ten digits in the format NXX-NXX-XXXX, where “N” can be any digit from 2–9 and “X” can contain the entire sequence of digits from 0–9. The first three digits are known as the Numbering Plan Area (NPA), area code, or area code. The second three-digit number block contains the Central office code as a prefix to which a four-digit suffix is added.
| ( | N | X | X | ) | X | X | X | - | X | X | X | X |
| ( | NPA | ) | prefix | - | suffix | |||||||
| ( | prefix | ) | Attendees | |||||||||
North American area codes (Numbering Plan Area [NPA], area code) are always the same length and consist of three digits. Large cities originally received lower digits and thus shorter area codes when using pulse dialing . Larger towns now have several area codes, sometimes several for the same area (overlays) . It is therefore not possible to roughly estimate the geographic location using the first digit. A distinction between landline numbers and mobile numbers is not possible in the North American numbering plan because mobile numbers are sorted under the usual area codes.
The subscriber number also has a fixed length of seven digits and consists of a three-digit prefix, which the exchange specifies, and four additional digits.
Initially, the area codes and the subscriber numbers were clearly distinguishable using the second digits: Area codes were given a 0 or 1 . In the meantime, however, both local subscriber numbers with 0 or 1 (since the end of the 1980s) and area codes with the digits 2 to 8 (since 1995) are assigned as the second digit. Other methods must therefore be used to differentiate.
The prefix 555 indicates fictional 555 phone numbers .
Dial plan
Originally, the second digit of the NPA was used to clearly differentiate whether it was a local call within an area code or whether the call went beyond this area. When dialing "202-555-1234" it was clear that 202 must be an area code, as there was no 0 in the second position for subscriber numbers ; “555-1234”, on the other hand, was clearly a local subscriber number, as area codes did not have a 5 in the second position. In order to clearly indicate a long-distance call as such, a 1 had to be preselected.
Since this has not been possible since the late 1980s, different dial plans have developed from region to region:
- There are areas in which the 1 must always be dialed first for long distance calls . Local area codes must not begin with the number 1 there .
- In other areas, the 1 serves as a sign that a number with a different local area code should then be dialed; Numbers within the same area code can be dialed directly.
- In some large cities, the full ten-digit number (NAP) must always be dialed, even for local calls. A preceding 1 is used to indicate a long-distance call.
history
The NANP was developed in 1947 by AT&T and Bell Laboratories to standardize the numbering plans for self-dialing devices in Direct Distance Dialing (DDD), so that long-distance calls are no longer dependent on the support of an operator . It was put into operation in 1951 to enable direct dialing of long distance calls. In the USA and Canada, 87 area codes were introduced according to the NYX scheme (N: 2–9, Y: 0 and 1, X: 0–9). Initially there were 86 geographical areas, each with an associated three-digit numbering plan area code (NPA) assigned. This plan provided for an expansion to up to 144 areas and an additional eight codes in the form N11 and N00 as Service Access Codes (SAC). In 1995, these 144 area assignments were reached and the NANP was expanded to 792 codes, some of which were reserved for future expansion.
Originally only intended for the USA and Canada, it was expanded to Bermuda and the British West Indies (including Trinidad and Tobago and the Bahamas ) from 1955 at the request of the British Colonial Office , as their historical telecommunications administration passed through Canada because they were all part of the British empires where connections to every country existed by telegraphs and the all-red-line system. At times, Mexico City and parts of northwestern Mexico were also included in the NANP, but were later switched to the uniform country code for Mexico . A certain connection between the Mexican area codes and the NANP still shines through. They are constructed according to the partially complementary scheme NYX (N: 2-9, Y: 1-9, X: 1-9), i. H. the second or third digit is never 0 . The first digit indicates the region. There are also a few two-digit area codes.
All countries share an area code system that has three-digit area codes. The system was relatively stable in the 1960s, 70s, and 80s, and many new area codes were added from the age of mobile communications. Mobile radio is operated using the normal area codes, so that mobile numbers cannot be distinguished from landline numbers from the outside.
In the first digit, the 0 was kept free for (manual) switching and the 1 for long-distance calls. The restriction of the second digit was used to distinguish between area codes and subscriber numbers.
At the beginning of the 1990s, however, NANPA (then part of Bellcore ) also had to assign the 0 and 1 in the middle to local exchanges due to the shortage of numbers ; In 1995 the area codes became scarce due to divisions and overlays , so that the digits 2 to 8 were assigned in the middle of the area codes; 9 is used for future extensions.
The dialing code +1 809, which was introduced on January 1, 1958 and is the same for the entire Caribbean region, was split between October 1, 1995 and June 1, 1998 among the numbers that are valid today.
The North American Numbering Plan Administration (NANPA) is now part of the private company NeuStar Inc. Due to the ongoing shortage of numbers, additional digits will have to be used within the numbers in the near future.
NANP number overview
The list includes independent states, British overseas territories (UK), outer territories of the United States (USA) and a Dutch part of the island ( NA ). US and Canadian states are listed separately.
The 87 area codes listed in bold (USA: 78, Canada: 9) have been in use since January 1, 1947. Another 56 numbers (USA: 48, Canada: 7, Caribbean: 1) with a 0 or 1 in second place were used in the years 1950 to 1994, all others (so far 267, of which Caribbean: 25, USA: 196, Canada: 46 ) Numbers from 1995 due to shortage of numbers, introduced or already reserved.
The ten number blocks 370–379 and 960–969 are reserved by the INC (Industry Numbering Committee).
The number blocks 29X – 99X (X = 0–8) are reserved for later extensions.
Another 208 numbers are still freely available.
Country overview of the NANP
| Country / Territory | Numbering Plan Area (NPA), area code |
|---|---|
| U.S. Virgin Islands (USA) | 340 (since July 1, 1997) |
| American Samoa (USA) | 684 |
| Anguilla (UK) | 264 (since March 31, 1997) |
| Antigua and Barbuda | 268 (since April 1, 1996) |
| Bahamas | 242 (since October 1, 1996) |
| Barbados | 246 (since July 1, 1996) |
| Bermuda (UK) | 441 (since October 1, 1995) |
| British Virgin Islands (UK) | 284 (since October 1, 1997) |
| Dominica | 767 (since October 1, 1997) |
| Dominican Republic | 809, 829, 849 (from 07/2009) |
| Grenada | 473 (since October 31, 1997) |
| Guam (USA) | 671 |
| Jamaica | 876 (since May 1, 1997) |
| Canada | several, see below |
| Cayman Islands (UK) | 345 (since September 1, 1996) |
| Montserrat (UK) | 664 (since July 1, 1996) |
| Northern Mariana Islands (USA) | 670 |
| Puerto Rico (USA) | 787 (since March 1, 1996), 939 |
| Sint Maarten (NL) | 721 |
| St. Kitts and Nevis | 869 (since October 1, 1996) |
| St. Lucia | 758 (since July 1, 1996) |
| St. Vincent and the Grenadines | 784 (since June 1, 1998) |
| Trinidad and Tobago | 868 (since June 1, 1997) |
| Turks and Caicos Islands (UK) | 649 (since June 1, 1997) |
| United States | several, see below |
The local networks 670 and 671 changed on July 1, 1997, 684 on October 2, 2004 from the number range +6 (Oceania / Pacific) to the number range +1, whereby they could each keep their own area code and now the +1 has to be dialed in addition .
Canadian provinces and territories in the NANP
| province | Numbering Plan Area (NPA), area code |
|---|---|
| Alberta | 403, 587, 780 |
| British Columbia | 236, 250, 604, 778 |
| Manitoba | 204, 431 |
| New Brunswick | 506 |
| Newfoundland and Labrador | 709 |
| Nova Scotia | 782, 902 |
| Northwest Territories | 867 |
| Nunavut | 867 |
| Ontario | 226, 249, 289, 343, 365, 416, 437, 519, 613, 647, 705, 807, 905 |
| Prince Edward Island | 782, 902 |
| Quebec | 418, 438, 450, 514, 579, 581, 819, 873 |
| Saskatchewan | 306, 639 |
| Yukon | 867 |
Other numbers already reserved for Canada : 257, 263, 273, 354, 367, 368, 382, 387, 428, 460, 468, 474, 487, 537, 548, 568, 584, 672, 683, 742, 753, 825 , 851, 871, 879, 942.
US states in the NANP
| State | Numbering Plan Area (NPA), area code |
|---|---|
| Alabama | 205 , 251, 256, 334, 659, 938 |
| Alaska | 907 |
| Arizona | 480, 520, 602, 623, 928 |
| Arkansas | 479, 501, 870 |
| Colorado | 303, 719, 720, 970 |
| Connecticut | 203, 475, 860, 959 |
| Delaware | 302 |
| Florida | 239, 305, 321, 352, 386, 407, 561, 689, 727, 754, 772, 786, 813, 850, 863, 904, 941, 954 |
| Georgia | 229, 404, 470, 478, 678, 706, 762, 770, 912 |
| Hawaii | 808 |
| Idaho | 208 , 986 |
| Illinois | 217, 224, 309, 312, 331, 447, 464, 618, 630, 708, 730, 773, 779, 815, 847, 872 |
| Indiana | 219 , 260, 317 , 463, 574, 765, 812 , 930 |
| Iowa | 319, 515, 563, 641, 712 |
| California | 209, 213, 310, 323, 341, 369, 408, 415, 424, 442, 510, 530, 559, 562, 619, 626, 627, 628, 650, 657, 661, 669, 707, 714, 747, 760, 764, 805, 818, 831, 858, 909, 916, 925, 935, 949, 951 |
| Kansas | 316, 620, 785, 913 |
| Kentucky | 270, 364, 502 , 606, 859 |
| Louisiana | 225, 318, 337, 504, 985 |
| Maine | 207 |
| Maryland | 227, 240, 301, 410, 443, 667 |
| Massachusetts | 339, 351, 413, 508, 617, 774, 781, 857, 978 |
| Michigan | 231, 248, 269, 313, 517, 586, 616, 679, 734, 810, 906, 947, 989 |
| Minnesota | 218, 320, 507, 612, 651, 763, 952 |
| Mississippi | 228, 601, 662, 769 |
| Missouri | 314, 417, 557, 573, 636, 660, 816, 975 |
| Montana | 406 |
| Nebraska | 308, 402 , 531 |
| Nevada | 702 , 725, 775 |
| New Hampshire | 603 |
| New Jersey | 201, 551, 609, 732, 848, 856, 862, 908, 973 |
| New Mexico | 505, 575 |
| new York | 212 , 315 , 332, 347, 516, 518 , 585, 607, 631, 646, 680, 716 , 718, 838, 845, 914 , 917, 929, 934 |
| North Carolina | 252, 336, 704 , 743, 828, 910, 919, 980, 984 |
| North Dakota | 701 |
| Ohio | 216, 220, 234, 283, 330, 380, 419, 440, 513, 567, 614, 740, 937 |
| Oklahoma | 405, 580, 918 |
| Oregon | 458, 503 , 541, 971 |
| Pennsylvania | 215 , 223, 267, 272, 412 , 484, 570, 610, 717 , 724, 814 , 878 |
| Rhode Island | 401 |
| South carolina | 803 , 843, 854, 864 |
| South Dakota | 605 |
| Tennessee | 423, 615, 629, 731, 865, 901 , 931 |
| Texas | 210, 214 , 254, 281, 325, 346, 361, 409, 430, 432, 469, 512 , 682, 713 , 726, 737, 806, 817, 830, 832, 903, 915 , 936, 940, 956, 972, 979 |
| Utah | 385, 435, 801 |
| Vermont | 802 |
| Virginia | 276, 434, 540, 571, 703 , 757, 804 |
| Washington | 206 , 253, 360, 425, 509, 564 |
| Washington, DC | 202 |
| West Virginia | 304 , 681 |
| Wisconsin | 262, 274, 414, 534, 608, 715, 920 |
| Wyoming | 307 |
Other numbers already reserved for the USA : 327, 353, 464, 582, 689, 835, 935, 943
Non-geographical area codes in the NANP
| meaning | Numbering Plan Area (NPA), area code |
|---|---|
| Inbound International | 456 |
| PCS mobile telephony | 500, 533 |
| Canadian services | 600 |
| Network operator services | 700 |
| U.S. government | 710 (since January 1, 1984) |
| Toll-Free | 800, 833, 844, 855, 866, 877, 888 (others reserved: 822, 880–887, 889) |
| Premium services | 900 |
| Service numbers / emergency call | N11: 211, 311, 411, 511, 611, 711, 811, 911 |
Other special numbers and area codes
| Manual mediation | 0 |
| Manual switching (long distance) | 00 |
| Area code for international connections (outside the NANP) | 011 |
| manual placement internationally (outside the NANP) | 01 |
| Call-by-call | 101-xxxx |
literature
- Inc Bell Communications Research: North American Number Plan Administrator's proposal on the future of numbering in world zone 1. Bellcore, 1992, OCLC 36020039 .
- James N. Deak: The North American numbering plan. A guide to preparing for the new number formats . North American Telecommunications Association, Washington, DC 1995, OCLC 33000836 .
- List of north american numbering plan area codes. Book On Demand Ltd, 2013, ISBN 978-5-513-12651-5 .
Web links
- North American Numbering Plan Administration on nationalnanpa.com
- Area code overview on nationalnanpa.com
- NPA Reports - Lists of area codes within the NANP on nationalnanpa.com
- North American Numbering Council on fcc.gov
- historical development of the country codes on wtng.info
Individual evidence
- ↑ NANPA. North American Numbering Plan Administration. nationalnanpa.com, accessed November 13, 2016 .
- ↑ E.164. The international public telecommunication numbering plan. itu.int, accessed on November 13, 2016 .
- ↑ NANPA. North American Numbering Plan Administration - About Us. nationalnanpa.com, accessed November 13, 2016 .
- ^ Structure of the international public telecommunication number according to ITU-T Recommendation E.164. In: Canadian Numbering Plan and Dialing Plan. Version 7.0. P. 4 ( cnac.ca ( Memento of the original from November 5, 2013 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this note. PDF) accessed on November 13, 2016.
- ↑ a b CNA - North American Numbering Plan. cnac.ca, accessed November 13, 2016 .
- ^ NANP North American Numbering Plan useful facts. howtocallabroad.com, accessed November 13, 2016 .
- ↑ The introduction was planned from May 31, 2010, but was postponed to September 30, 2011. Introduction of NPA 721 (Sint Maarten). (PDF) on nationalnanpa.com.
- ↑ Canadian Area Code Maps on cnac.ca
