{ "url": "https://phonelookup.dev/prefix/us-251", "npa": "251", "slug": "us-251", "iso": "US", "country": "United States", "regions": [ { "code": "AL", "name": "Alabama", "exchanges": 543 } ], "exchanges": 543, "known": 529, "byLineType": { "fixed_line": 236, "mobile": 184, "unknown": 14, "voip": 109 }, "carriers": [ { "name": "AT&T", "exchanges": 173, "byLineType": { "fixed_line": 98, "mobile": 71, "voip": 4 }, "ranges": [ "204", "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" ] }, { "name": "Onvoy", "exchanges": 66, "byLineType": { "voip": 66 }, "ranges": [ "203", "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" ] }, { "name": "Lumen", "exchanges": 55, "byLineType": { "fixed_line": 54, "voip": 1 }, "ranges": [ "202", "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" ] }, { "name": "Verizon", "exchanges": 43, "byLineType": { "fixed_line": 5, "mobile": 38 }, "ranges": [ "222", "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" ] }, { "name": "T-Mobile", "exchanges": 40, "byLineType": { "mobile": 40 }, "ranges": [ "200", "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" ] }, { "name": "Paetec Itel", "exchanges": 19, "byLineType": { "fixed_line": 19 }, "ranges": [ "206", "210", "212", "218", "226", "231", "237", "239", "245", "249", "268", "273", "338", "378", "386", "544", "586", "622", "706" ] }, { "name": "Emergency Networks", "exchanges": 17, "byLineType": { "mobile": 17 }, "ranges": [ "364–365", "372", "374", "448–449", "505", "566", "606", "780", "820", "830", "840", "860", "870", "890", "901" ] }, { "name": "MCC Telephony", "exchanges": 17, "byLineType": { "fixed_line": 17 }, "ranges": [ "224", "240", "256", "262", "271", "290", "299", "306", "312", "314", "322", "324", "357", "488", "500", "600", "677" ] }, { "name": "Frontier", "exchanges": 15, "byLineType": { "fixed_line": 15 }, "ranges": [ "248", "258", "267", "282", "294", "368", "446", "564", "575", "577", "743", "746", "765", "789", "862" ] }, { "name": "Fractel", "exchanges": 11, "byLineType": { "voip": 11 }, "ranges": [ "336", "346", "356", "465", "529", "699", "724", "758", "766", "842", "877" ] }, { "name": "Telepak Networks", "exchanges": 10, "byLineType": { "fixed_line": 10 }, "ranges": [ "201", "300–301", "410", "425", "445", "491", "620", "638", "923" ] }, { "name": "Millry Telephone Company", "exchanges": 7, "byLineType": { "fixed_line": 7 }, "ranges": [ "542", "754", "777", "827", "843", "846–847" ] }, { "name": "Bandwidth.com", "exchanges": 6, "byLineType": { "voip": 6 }, "ranges": [ "260", "289", "291–292", "486", "647" ] }, { "name": "SouthernLINC Wireless", "exchanges": 6, "byLineType": { "mobile": 6 }, "ranges": [ "238", "254–255", "331", "424", "581" ] }, { "name": "USA Mobility", "exchanges": 6, "byLineType": { "mobile": 6 }, "ranges": [ "352", "371", "417", "568", "582", "617" ] }, { "name": "COMMIO LLC", "exchanges": 5, "byLineType": { "voip": 5 }, "ranges": [ "464", "466", "474", "481", "520" ] }, { "name": "Brightlink Communications", "exchanges": 4, "byLineType": { "mobile": 1, "voip": 3 }, "ranges": [ "303", "335", "381", "506" ] }, { "name": "Cellular South", "exchanges": 3, "byLineType": { "mobile": 3 }, "ranges": [ "366–367", "550" ] }, { "name": "Comcast", "exchanges": 3, "byLineType": { "voip": 3 }, "ranges": [ "305", "462", "725" ] }, { "name": "TELNYX", "exchanges": 3, "byLineType": { "voip": 3 }, "ranges": [ "315", "318", "353" ] }, { "name": "HD Carrier", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "531", "799" ] }, { "name": "Pine Belt Telephone", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "307", "400" ] }, { "name": "TDS Telecom", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "275", "360" ] }, { "name": "Airus Inc", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "426" ] }, { "name": "Bhn Ip Enabled Services", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "280" ] }, { "name": "CSC Wireless LLC", "exchanges": 1, "byLineType": { "mobile": 1 }, "ranges": [ "328" ] }, { "name": "Castleberry Telephone Company", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "966" ] }, { "name": "Dish Wireless", "exchanges": 1, "byLineType": { "mobile": 1 }, "ranges": [ "429" ] }, { "name": "Exiant", "exchanges": 1, "byLineType": { "voip": 1 }, "ranges": [ "587" ] }, { "name": "Hypercube Telecom", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "319" ] }, { "name": "IP Horizon", "exchanges": 1, "byLineType": { "voip": 1 }, "ranges": [ "373" ] }, { "name": "Nuso", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "427" ] }, { "name": "Terra Nova Telecom", "exchanges": 1, "byLineType": { "voip": 1 }, "ranges": [ "998" ] }, { "name": "Twilio International", "exchanges": 1, "byLineType": { "voip": 1 }, "ranges": [ "501" ] }, { "name": "Vonage", "exchanges": 1, "byLineType": { "voip": 1 }, "ranges": [ "283" ] }, { "name": "Wavenation", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "534" ] }, { "name": "Wide Voice", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "541" ] } ], "grid": "mffvfvfmfmfufmmmffffvfmmfmfmmmmfmmmmmfmfffmfmfffffvvfmmmfvfmvmfvmvfffmffffvffmmffmfvmvvfmvfvvmfmfvmfffmmfvffvffufvfvffvfmmfmfmfmmmfmmvvvvvfvffffffvvvmvvmvmvvfmmffmmmmmmfffmmvmfmmfmfvmvmvfmvvvmmmmmmvmvfmmmmfmmfmfummffmmfmvmmmmfffmmvfffffffffvfffvfffmmfvfvmmffmfffvmvvvvvvffffvmfmffvvvmmmvmfmmffmfmmmmffvmfmmvmmfmuvmmvmfmvvvvvmmmmmvvvmmfmmmmmffffff----mvvvmuvv------f-mvm--vv-ff-ff-fmmm--fvmm-m-m---m-mf-f-mmmf-mmu---vfm--fffm-ff----f-fff--ff---fmf-vmffvfffmm---fff-vff--------f-fvfm--------mf---f--f-vu-----f--mvu--m-m----m--vv-m----f----------ff-fm---mmmf---v------fvm-mff----ff--m-----m--f---------vv-m------fvu--------m---f--f-fm---------m-vf--ff--vv--------mff--fffv-m--f---v--v-------v-m----m----vm--------vu-----------f----ffmf-----f----ffffffffu-f--f-fuufff-fffff-ffffffu-mmff----fffff-------vv", "patterns": { "all": "^\\+1251[2-9]\\d{6}$", "fixed_line": "^\\+1251(?:2(?:0[12468]|1[026-9]|2[146]|3[179]|4[0135-9]|5[268]|6[26-8]|7[0-3569]|8[027]|9[0469])|3(?:0[014679]|1[024679]|2[246]|3[08]|4[0-5]|57|6[0189]|7[058]|8[06])|4(?:0[058]|1[0458]|2[5-7]|3[1-9]|4[1-35-7]|5[02679]|6[01]|7[0-3689]|88|9[1249])|5(?:0[039]|17|[36]4|4[0-5]|7[4578]|8[06])|6(?:0[027]|16|[26][0-256]|3[13-589]|4[359]|5[02-4]|7[579]|9[047])|7(?:06|32|4[346]|54|65|7[0167]|89)|8(?:09|2[479]|4[367]|6[125-7]|73)|9(?:2[389]|3[17]|4[2-9]|5[257]|6[0-24-8]|7[0-5]|8[016-9]|90))\\d{4}$", "mobile": "^\\+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}$", "voip": "^\\+1251(?:2(?:0[35]|20|5[017]|6[035]|74|8[3569]|9[127])|3(?:0[58]|1[358]|3[3-79]|4[6-8]|5[01356]|73|8[13589]|9[079])|4(?:[23]0|4[04]|5[13]|6[24-9]|74|8[0-26])|5(?:0[16]|1[259]|2[0-39]|3[01]|5[1-367]|[68]7|7[12])|6(?:15|47|51|64|78|99)|7(?:10|2[45]|58|66|99)|8(?:[01]0|42|5[01]|68|77|8[08])|9(?:[01]0|9[89]))\\d{4}$" }, "sandbox": { "input": "+12515550123", "valid": true, "type": "Fixed line or mobile", "region": "US", "formats": { "e164": "+12515550123", "international": "+1 251-555-0123", "national": "(251) 555-0123", "rfc3966": "tel:+1-251-555-0123" }, "parts": { "countryCode": "+1", "destinationCode": "251", "destinationKind": "area code", "subscriber": "5550123" } }, "faq": [ { "question": "Where is area code 251?", "answer": "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." }, { "question": "Is a 251 number mobile or landline?", "answer": "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." }, { "question": "Which carriers have numbers in area code 251?", "answer": "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." }, { "question": "How do I validate a 251 phone number?", "answer": "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." } ], "neighbours": { "sameRegion": [ "us-205", "us-256", "us-334", "us-659", "us-938" ], "previous": "ca-250", "next": "us-252" }, "meta": { "dataAsOf": "2026-10-25", "dataPoints": 543, "references": [ { "authority": "NANPA", "title": "North American Numbering Plan Administrator", "url": "https://nanpa.com/" }, { "authority": "CNAC", "title": "Canadian Numbering Administrator", "url": "https://www.cnac.ca/" }, { "authority": "ITU", "title": "National numbering plan: United States", "url": "https://www.itu.int/oth/T02020000DE/en" } ] } }