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251

Area code 251

Alabama, United States

National (251) 555-0123, E.164 +12515550123

How the 543 central office codes (exchanges) of area code 251 were allocated, from the North American Numbering Plan's records: to which carrier, as which line type. A 251 number is mobile, fixed line or VoIP according to its exchange, the three digits after the area code; the allocation is the original one (below).

At a glance

Country code
+1
State
AL
Exchanges on record
543
Carriers on record
37
Exchanges of 251 by the line type they were allocated as
  • Mobile 184 (34%)
  • Fixed line 236 (43%)
  • VoIP 109 (20%)
  • No line type on record 14 (3%)
  • 543 exchanges on record

Most exchanges: AT&T 173, Onvoy 66, Lumen 55.

Check a number

Valid fixed line or mobile number in the United States.

+1
country code
251
area code
5550123
subscriber number
CountryUnited States numbering plan
Line typeFixed line or mobile
Carrier the block was allocated toNo carrier on record for this prefix
E.164+12515550123
International+1 251-555-0123
National(251) 555-0123
RFC 3966tel:+1-251-555-0123

Source: North American Numbering Plan Administrator (NANPA); Canadian Numbering Administrator (CNAC); National numbering plan: United States (ITU)

The example is 251-555-0123: 555-0100 to 555-0199 are set aside for fictional use in every area code.

The exchange map

Every exchange of 251, by the line type it was allocated as

One cell per exchange: blocks 251 2xx to 251 9xx; in each block the row is the tens digit, the column the units digit.

251 2xx251 3xx251 4xx251 5xx251 6xx251 7xx251 8xx251 9xx
  • Mobile 184
  • Fixed line 236
  • VoIP 109
  • No line type on record 14
  • Not on record 257

Formats and patterns

E.164+12515550123
International+1 251-555-0123
National(251) 555-0123
RFC 3966 (tel: URI)tel:+1-251-555-0123

Any 251 number, in E.164

^\+1251[2-9]\d{6}$

+1, the area code, a central office code that does not start with 0 or 1, then four digits.

Mobile exchanges (184 on record)

^\+1251(?:2(?:0[079]|1[3-5]|2[2357-9]|3[02-68]|4[24]|5[3-59]|6[149]|7[78]|8[148]|9[358])|3(?:0[23]|2[01357-9]|3[12]|49|5[2489]|6[2-7]|7[124679]|8[247]|9[1-68])|4(?:0[1-4679]|1[23679]|2[1-489]|4[89]|5[458]|63|7[57]|8[3-579]|9[035-8])|5(?:0[24578]|1[03468]|2[4-8]|3[235-9]|5[04]|6[68]|8[1-389]|9[1379])|6(?:0[4-69]|1[07]|23|4[48]|5[56]|8[09])|7(?:09|1[46]|2[17]|47|5[1-3]|6[79]|8[06])|8(?:02|[2-467]0|9[05])|9(?:01|30|7[89]))\d{4}$

Fixed line exchanges (236 on record)

^\+1251(?:2(?:0[12468]|1[026-9]|2[146]|3[179]|4[0135-9]|5[268]|6[26-8]|7[0-3569]|8[027]|9[0469])|3(?:0[014679]|1[024679]|2[246]|3[08]|4[0-5]|57|6[0189]|7[058]|8[06])|4(?:0[058]|1[0458]|2[5-7]|3[1-9]|4[1-35-7]|5[02679]|6[01]|7[0-3689]|88|9[1249])|5(?:0[039]|17|[36]4|4[0-5]|7[4578]|8[06])|6(?:0[027]|16|[26][0-256]|3[13-589]|4[359]|5[02-4]|7[579]|9[047])|7(?:06|32|4[346]|54|65|7[0167]|89)|8(?:09|2[479]|4[367]|6[125-7]|73)|9(?:2[389]|3[17]|4[2-9]|5[257]|6[0-24-8]|7[0-5]|8[016-9]|90))\d{4}$

VoIP exchanges (109 on record)

^\+1251(?:2(?:0[35]|20|5[017]|6[035]|74|8[3569]|9[127])|3(?:0[58]|1[358]|3[3-79]|4[6-8]|5[01356]|73|8[13589]|9[079])|4(?:[23]0|4[04]|5[13]|6[24-9]|74|8[0-26])|5(?:0[16]|1[259]|2[0-39]|3[01]|5[1-367]|[68]7|7[12])|6(?:15|47|51|64|78|99)|7(?:10|2[45]|58|66|99)|8(?:[01]0|42|5[01]|68|77|8[08])|9(?:[01]0|9[89]))\d{4}$

The exchange patterns follow the original allocations; a number ported since keeps its digits but not necessarily its carrier or its line type.

Carriers and their exchanges

Every carrier holding exchanges in 251, with the exchanges allocated to it (the three digits after the area code).

CarrierExchangesMobileFixed lineVoIPExchanges held
AT&T17371984204, 207–208, 213–214, 219, 221, 223, 225, 227–228, 246–247, 253, 261, 264–266, 274, 278–279, 281, 286, 293, 296, 304, 309–310, 316, 320, 323, 325, 329–330, 332, 340–345, 348, 358, 363, 369–370, 376–377, 380, 403–406, 408, 414–415, 431–439, 441–443, 447, 450, 452, 454–457, 459–461, 463, 470–473, 475–479, 483, 485, 489–490, 492–493, 496–499, 502, 507, 509–510, 514, 516, 524, 526–528, 532, 535–537, 539, 574, 578, 580, 588–589, 591, 593, 599, 602, 604–605, 607, 610, 621, 625–626, 631, 633–635, 639, 643, 645, 649, 653–654, 656, 660–662, 665–666, 675, 679–680, 689–690, 694, 709, 714, 751–752, 769–771, 776, 802, 809, 829, 866–867, 895, 928–929, 931, 937, 944, 973, 978, 990
Onvoy660066203, 205, 220, 250–251, 257, 263, 285, 297, 313, 333–334, 337, 339, 347, 350–351, 355, 383, 385, 388–390, 397, 399, 420, 430, 440, 444, 451, 453, 467–469, 480, 482, 512, 515, 519, 521–523, 530, 551–553, 556–557, 567, 571–572, 615, 651, 664, 678, 710, 800, 810, 850–851, 868, 880, 888, 900, 910, 999
Lumen550541202, 216–217, 241, 252, 272, 276, 308, 317, 326, 361, 375, 418, 494, 517, 540, 543, 545, 616, 650, 652, 732, 744, 824, 861, 865, 873, 942–943, 945–949, 952, 955, 957, 960–962, 964–965, 967–968, 970–972, 974–975, 980–981, 986–989
Verizon433850222, 230, 232, 234, 236, 242–244, 270, 277, 287–288, 295, 298, 302, 327, 349, 354, 359, 362, 387, 395, 401–402, 421–423, 428, 484, 487, 495, 503–504, 513, 525, 533, 538, 597, 697, 721, 727, 753, 979
T-Mobile404000200, 209, 215, 229, 233, 235, 259, 269, 284, 321, 379, 382, 384, 391–394, 396, 398, 407, 409, 412–413, 416, 419, 458, 508, 518, 554, 583, 609, 623, 644, 648, 655, 716, 747, 767, 786, 930
Paetec Itel190190206, 210, 212, 218, 226, 231, 237, 239, 245, 249, 268, 273, 338, 378, 386, 544, 586, 622, 706
Emergency Networks171700364–365, 372, 374, 448–449, 505, 566, 606, 780, 820, 830, 840, 860, 870, 890, 901
MCC Telephony170170224, 240, 256, 262, 271, 290, 299, 306, 312, 314, 322, 324, 357, 488, 500, 600, 677
Frontier150150248, 258, 267, 282, 294, 368, 446, 564, 575, 577, 743, 746, 765, 789, 862
Fractel110011336, 346, 356, 465, 529, 699, 724, 758, 766, 842, 877
Telepak Networks100100201, 300–301, 410, 425, 445, 491, 620, 638, 923
Millry Telephone Company7070542, 754, 777, 827, 843, 846–847
Bandwidth.com6006260, 289, 291–292, 486, 647
SouthernLINC Wireless6600238, 254–255, 331, 424, 581
USA Mobility6600352, 371, 417, 568, 582, 617
COMMIO LLC5005464, 466, 474, 481, 520
Brightlink Communications4103303, 335, 381, 506
Cellular South3300366–367, 550
Comcast3003305, 462, 725
TELNYX3003315, 318, 353
HD Carrier2002531, 799
Pine Belt Telephone2020307, 400
TDS Telecom2020275, 360
Airus Inc1010426
Bhn Ip Enabled Services1010280
CSC Wireless LLC1100328
Castleberry Telephone Company1010966
Dish Wireless1100429
Exiant1001587
Hypercube Telecom1010319
IP Horizon1001373
Nuso1010427
Terra Nova Telecom1001998
Twilio International1001501
Vonage1001283
Wavenation1010534
Wide Voice1010541

Questions developers ask

Where is area code 251?
Area code 251 is in Alabama, in the United States: all 543 of its exchanges on record are there. From abroad it is dialled +1 251, then the seven-digit number.
Is a 251 number mobile or landline?
Either: in the North American Numbering Plan the line type belongs to the exchange (the three digits after the area code), not to the area code. Of the 543 exchanges on record in 251, 184 (34%) were allocated as mobile, 236 (43%) as fixed line, 109 (20%) as VoIP and 14 (3%) have no line type on record. A number can have been ported since, to another carrier and even to another line type.
Which carriers have numbers in area code 251?
37 carriers hold exchanges in 251 on record; the most: AT&T (173), Onvoy (66) and Lumen (55). These are the original allocations: with number portability, a number may be served by another carrier today, which only a live carrier lookup (an HLR or MNP query) can tell.
How do I validate a 251 phone number?
In E.164 a 251 number matches ^\+1251[2-9]\d{6}$: +1, the area code, a central office code that does not start with 0 or 1, then four digits. Written nationally it reads (251) 555-0123. The exchange patterns on this page narrow it to the exchanges allocated as mobile, fixed line or VoIP.