443
Area code 443
Maryland, United States
National (443) 555-0123, E.164 +14435550123
How the 800 central office codes (exchanges) of area code 443 were allocated, from the North American Numbering Plan's records: to which carrier, as which line type. A 443 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
- MD
- Exchanges on record
- 800
- Carriers on record
- 16
- Mobile 312 (39%)
- Fixed line 425 (53%)
- VoIP 49 (6%)
- No line type on record 14 (2%)
- 800 exchanges on record
Most exchanges: Verizon 231, Paetec Itel 153, AT&T 121.
Check a number
Valid fixed line or mobile number in the United States.
+1
country code
443
area code
5550123
subscriber number
| Country | United States numbering plan |
|---|---|
| Line type | Fixed line or mobile |
| Carrier the block was allocated to | No carrier on record for this prefix |
| E.164 | +14435550123 |
| International | +1 443-555-0123 |
| National | (443) 555-0123 |
| RFC 3966 | tel:+1-443-555-0123 |
Source: North American Numbering Plan Administrator (NANPA); Canadian Numbering Administrator (CNAC); National numbering plan: United States (ITU)
The example is 443-555-0123: 555-0100 to 555-0199 are set aside for fictional use in every area code.
The exchange map
One cell per exchange: blocks 443 2xx to 443 9xx; in each block the row is the tens digit, the column the units digit.
- Mobile 312
- Fixed line 425
- VoIP 49
- No line type on record 14
Formats and patterns
| E.164 | +14435550123 |
|---|---|
| International | +1 443-555-0123 |
| National | (443) 555-0123 |
| RFC 3966 (tel: URI) | tel:+1-443-555-0123 |
Any 443 number, in E.164
^\+1443[2-9]\d{6}$+1, the area code, a central office code that does not start with 0 or 1, then four digits.
Mobile exchanges (312 on record)
^\+1443(?:2(?:0[124-8]|1[04]|2[356]|3[59]|4[038]|5[02-578]|7[17]|8[026]|9[389])|3(?:0[169]|1[045]|2[46]|3[356]|40|5[09]|6[256]|7[03578]|8[168]|9[78])|4(?:0[14]|1[3-68]|2[12]|3[589]|47|54|6[235-9]|7[3478]|8[08]|9[367])|5(?:0[069]|1[035]|2[0157-9]|3[1246-8]|4[07]|5[34]|6[0236]|7[01]|80|9[179])|6(?:0[0248]|1[03-57-9]|2[1-49]|3[01356]|42|5[1-35]|6[78]|7[67]|8[0-467]|9[01459])|7(?:0[57]|1[47]|2[1-36]|3[569]|4[2-5]|5[024689]|6[1-589]|7[145]|8[3689]|9[0149])|8(?:0[0-7]|1[02-49]|2[1-79]|3[14589]|4[024-8]|5[0-47-9]|6[02-69]|7[1568]|8[129]|9[0457])|9(?:0[02-57-9]|1[0356]|2[4589]|3[024-689]|4[158]|5[2356]|6[02568]|7[057-9]|8[0135-7]|9[13-6]))\d{4}$Fixed line exchanges (425 on record)
^\+1443(?:2(?:0[039]|1[235-9]|2[0147-9]|3[0-46-8]|4[24-79]|5[69]|6[0-57-9]|7[02-4689]|8[13-57-9]|9[0-25-7])|3(?:0[023578]|1[23689]|2[0-357-9]|3[0-247-9]|4[1-9]|5[1-7]|6[01347-9]|7[1246]|8[02-579]|9[1-6])|4(?:0[0236-9]|1[279]|2[3-9]|3[0-367]|4[0-24-69]|5[0-257-9]|6[014]|7[0-2569]|8[1-79]|9[28])|5(?:0[1-578]|1[247-9]|2[2-46]|3[0359]|4[13-689]|5[0-26-8]|6[1457-9]|[78][2-9]|9[02-46])|6(?:0[135-79]|1[26]|2[05-8]|3[247-9]|4[013-9]|5[0467]|6[1-69]|7[0-589]|8[589]|9[236-8])|7(?:0[1-4689]|1[025689]|2[0457-9]|3[0-478]|4[016-9]|5[1357]|6[067]|7[0237-9]|8[0247]|9[235-8])|8(?:09|1[5-8]|2[08]|3[02367]|4[139]|5[56]|6[178]|7[02479]|8[03-8]|9[13689])|9(?:01|1[2489]|2[0-367]|3[137]|4[02367]|5[147]|6[1479]|7[2-4]|8[489]|9[27-9]))\d{4}$VoIP exchanges (49 on record)
^\+1443(?:2(?:22|[45]1|66|75|94)|3(?:04|17|58|79|9[09])|4(?:05|[12]0|34|4[38]|5[36]|9[01459])|5(?:16|42|59|81|9[58])|6(?:5[89]|60)|7(?:13|76|8[15])|8(?:08|73|92)|9(?:06|17|4[49]|63|71|82|90))\d{4}$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 443, with the exchanges allocated to it (the three digits after the area code).
| Carrier | Exchanges | Mobile | Fixed line | VoIP | Exchanges held |
|---|---|---|---|---|---|
| Verizon | 231 | 121 | 110 | 0 | 200, 202–203, 205–206, 213, 220, 223–224, 235, 243, 248–249, 252, 257, 259–263, 274, 276, 279, 281, 285–289, 293, 299, 308, 334, 340, 350, 353, 357, 359, 367, 377, 386, 388, 394–395, 397, 400–401, 407–408, 430, 433, 436, 438–440, 444–446, 455, 458, 460, 462, 465, 475–480, 482, 493, 498, 503, 509–510, 512, 515, 518, 521, 523–524, 534–535, 537, 543, 546–548, 552–553, 556–558, 566, 568, 571–572, 576, 578, 588, 591, 602, 604, 610, 612, 614–615, 617–619, 624, 630, 634, 637, 642–643, 650–651, 654, 663, 667, 678, 681–684, 686–687, 690, 692, 695, 699, 701, 703, 705, 710, 717, 720–721, 734, 741, 743, 745, 750, 752–755, 758–759, 770–771, 773, 775, 777–779, 782–783, 786, 792–793, 795–797, 812–817, 823, 826–827, 834–836, 841–845, 847, 849, 853, 861–863, 868–869, 878–879, 885, 890–891, 893, 895, 900, 902–904, 907–909, 915, 924, 928, 930–931, 934, 938, 952–953, 955, 960, 962, 966–967, 970, 973, 977–979, 981, 984, 986–987, 991, 997–999 |
| Paetec Itel | 153 | 0 | 153 | 0 | 209, 212, 216, 227–230, 233–234, 238, 242, 245, 247, 256, 265, 270, 283, 318–319, 321–323, 325, 327–328, 330–332, 338–339, 342, 347, 351, 372, 374, 383–384, 409, 419, 426, 429, 432, 442, 449, 451–452, 459, 461, 464, 470–471, 481, 504, 508, 514, 522, 526, 530, 539, 541, 544, 549, 561, 565, 573–575, 577, 579, 582–585, 587, 589, 593, 601, 603, 605–607, 609, 616, 626, 632, 639–640, 644–647, 649, 656, 661–662, 664, 669–670, 673, 675, 685, 688–689, 696, 702, 704, 706, 709, 712, 715–716, 718–719, 724–725, 727–730, 737–738, 748–749, 751, 757, 766–767, 772, 780, 787, 820, 828, 830, 833, 837, 855, 867, 872, 874, 884, 887–888, 901, 919, 921–923, 940, 947, 954, 969, 972, 989 |
| AT&T | 121 | 71 | 50 | 0 | 201, 204, 214, 231, 239–240, 253, 255, 258, 267, 272–273, 280, 297–298, 301, 310, 315, 326, 333, 343, 348, 360, 364, 370, 376, 381, 392, 402, 406, 412, 417, 421–422, 424–425, 437, 441, 447, 457, 467, 469, 474, 488–489, 500, 502, 507, 513, 520, 525, 531, 533, 540, 562, 608, 613, 620, 631, 635, 648, 655, 668, 671–672, 674, 676, 679, 691, 693, 698, 714, 731–733, 735–736, 742, 756, 760, 765, 774, 784, 789, 791, 794, 799, 831, 838, 840, 846, 852, 860, 875, 880, 883, 886, 896–897, 905, 910, 914, 918, 920, 933, 935–937, 941–943, 945, 956–957, 968, 974–975, 980, 994–996 |
| T-Mobile | 120 | 120 | 0 | 0 | 207–208, 210, 225–226, 250, 254, 271, 277, 282, 306, 309, 314, 324, 335–336, 362, 365–366, 373, 375, 378, 398, 404, 413–416, 418, 435, 454, 463, 466, 468, 473, 496–497, 506, 527–529, 532, 536, 538, 554, 560, 563, 570, 580, 597, 599, 600, 621–623, 629, 633, 636, 652–653, 677, 680, 694, 707, 722–723, 726, 739, 744, 761–764, 768–769, 788, 790, 800–807, 810, 819, 821–822, 824–825, 829, 839, 848, 850–851, 854, 857–859, 864–866, 871, 876, 881–882, 889, 894, 913, 916, 925, 929, 932, 939, 948, 965, 983, 985, 993 |
| Lumen | 75 | 0 | 74 | 1 | 218–219, 221, 244, 290–292, 295–296, 300, 302–303, 305, 307, 312–313, 316, 320, 329, 341, 345, 352, 354–356, 371, 380, 391, 393, 396, 403, 410, 423, 450, 472, 483–487, 492, 501, 505, 517, 519, 545, 550–551, 564, 567, 569, 590, 594, 625, 627, 641, 657, 666, 708, 740, 746, 798, 809, 818, 832, 870, 877, 898–899, 926–927, 951, 964, 988, 992 |
| CoreTel | 34 | 0 | 34 | 0 | 215, 217, 232, 236–237, 246, 264, 268–269, 284, 337, 344, 346, 349, 361, 363, 368–369, 382, 385, 387, 389, 427–428, 431, 586, 592, 596, 628, 665, 747, 856, 912, 946 |
| Bandwidth.com | 18 | 0 | 0 | 18 | 266, 294, 304, 317, 390, 420, 490, 494–495, 499, 595, 598, 776, 808, 892, 963, 971, 990 |
| Onvoy | 14 | 0 | 0 | 14 | 222, 241, 251, 399, 453, 491, 516, 581, 658–659, 781, 785, 873, 917 |
| Comcast | 10 | 0 | 0 | 10 | 275, 379, 405, 448, 456, 542, 559, 660, 944, 949 |
| Global NAPS | 2 | 0 | 2 | 0 | 638, 697 |
| Peerless Network | 2 | 0 | 0 | 2 | 713, 906 |
| YMax Communications | 2 | 0 | 0 | 2 | 358, 982 |
| COMMIO LLC | 1 | 0 | 0 | 1 | 443 |
| Global Telecom Brokers | 1 | 0 | 1 | 0 | 278 |
| TELNYX | 1 | 0 | 0 | 1 | 434 |
| West Telecom | 1 | 0 | 1 | 0 | 961 |
Questions developers ask
- Where is area code 443?
- Area code 443 is in Maryland, in the United States: all 800 of its exchanges on record are there. From abroad it is dialled +1 443, then the seven-digit number.
- Is a 443 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 800 exchanges on record in 443, 312 (39%) were allocated as mobile, 425 (53%) as fixed line, 49 (6%) as VoIP and 14 (2%) 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 443?
- 16 carriers hold exchanges in 443 on record; the most: Verizon (231), Paetec Itel (153) and AT&T (121). 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 443 phone number?
- In E.164 a 443 number matches ^\+1443[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 (443) 555-0123. The exchange patterns on this page narrow it to the exchanges allocated as mobile, fixed line or VoIP.