{ "url": "https://phonelookup.dev/prefix/us-423", "npa": "423", "slug": "us-423", "iso": "US", "country": "United States", "regions": [ { "code": "TN", "name": "Tennessee", "exchanges": 779 } ], "exchanges": 779, "known": 765, "byLineType": { "fixed_line": 353, "mobile": 265, "unknown": 14, "voip": 147 }, "carriers": [ { "name": "AT&T", "exchanges": 216, "byLineType": { "fixed_line": 132, "mobile": 80, "voip": 4 }, "ranges": [ "204", "208–209", "219", "222–223", "231", "235", "237", "242–244", "249", "258", "263", "265–268", "272", "276", "284–285", "287", "296", "298", "304", "310", "315", "317–318", "320–321", "326", "329–330", "332", "334", "336–339", "342", "344–345", "351", "355–356", "362", "364–367", "375", "386–387", "394", "404", "408", "420", "425", "429", "442", "445", "448", "451–452", "458–459", "463", "465", "471–473", "476", "478–479", "485", "487–490", "492–493", "495–496", "499", "507–508", "510", "513", "517", "522", "539", "553", "559", "562–563", "566–567", "570", "576–577", "580–582", "584–587", "589", "596", "598", "601", "603", "613–614", "622–625", "629", "634–635", "640", "642", "644–645", "649", "653", "658–659", "668", "683", "685", "687", "695", "697–698", "704", "706–707", "728", "733", "737–738", "741", "744–748", "751–752", "755–757", "760", "763", "767", "771", "774–776", "778", "780", "784–785", "800", "807", "810", "816", "821–822", "825", "827", "829", "835", "837–838", "842–843", "846–847", "849", "855", "867", "869–871", "874–877", "882–883", "886", "890", "892–894", "899", "902–903", "907", "912", "918", "920–921", "923", "942", "954", "961", "987", "991", "994" ] }, { "name": "Lumen", "exchanges": 129, "byLineType": { "fixed_line": 127, "voip": 2 }, "ranges": [ "200–201", "207", "212", "217–218", "224", "229–230", "232", "234", "236", "238–239", "245–247", "256–257", "262", "274", "278–279", "282–283", "288", "294", "297", "299", "323", "325", "343", "348–349", "354", "357", "359", "372", "378", "390–392", "396", "410", "422", "431", "433–439", "443", "453–455", "461", "467", "474", "477", "482", "484", "491", "516", "525–526", "538", "542–543", "545–547", "551", "578", "610", "626", "636", "638–639", "652", "664–665", "693", "702", "722–723", "725", "727", "735", "743", "753", "761", "764", "768", "772", "781", "783", "787–789", "793", "798–799", "809", "834", "844", "851–852", "854", "857", "878", "896–897", "913", "915", "917", "926", "928–929", "938", "952–953", "968", "973", "975", "979", "989–990" ] }, { "name": "Verizon", "exchanges": 84, "byLineType": { "fixed_line": 4, "mobile": 80 }, "ranges": [ "202", "215", "240–241", "260", "269–271", "280", "290", "300–301", "306", "309", "312", "322", "327", "335", "341", "360–361", "368", "389", "413", "415–419", "426", "440", "444", "457", "470", "480", "483", "486", "494", "502", "506", "512", "523", "534–535", "552", "564", "571", "588", "599", "605", "607–609", "612", "618–621", "637", "650", "661", "667", "680–682", "699", "715", "718", "726", "732", "736", "740", "742", "754", "762", "797", "802", "813", "836", "845", "863", "914", "956", "969" ] }, { "name": "T-Mobile", "exchanges": 73, "byLineType": { "mobile": 73 }, "ranges": [ "213", "227", "251", "255", "273", "277", "289", "291–293", "313–314", "316", "331", "333", "340", "358", "371", "381", "383–384", "388", "395", "398", "400", "405", "421", "432", "441", "464", "466", "475", "497", "503–505", "518", "521", "530", "544", "557", "593", "595", "617", "646–647", "676–677", "694", "696", "708", "717", "749", "773", "791", "817", "823", "833", "841", "856", "889", "895", "898", "943", "946", "948", "951", "957", "963", "967", "972", "996", "999" ] }, { "name": "Sinch (Inteliquent)", "exchanges": 54, "byLineType": { "voip": 54 }, "ranges": [ "205", "370", "373–374", "376", "379", "382", "427", "468", "500", "509", "515", "540", "558", "560–561", "591", "594", "604", "616", "662", "666", "669", "674–675", "678–679", "686", "691", "703", "734", "759", "766", "770", "777", "786", "805", "818", "820", "824", "830", "840", "850", "858–859", "862", "868", "879–880", "885", "888", "900", "919", "980" ] }, { "name": "Paetec Itel", "exchanges": 33, "byLineType": { "fixed_line": 33 }, "ranges": [ "216", "220", "228", "252", "254", "275", "303", "307–308", "352–353", "385", "401", "424", "428", "449", "520", "529", "532", "536–537", "673", "709", "714", "716", "724", "758", "779", "782", "794", "826", "933", "939" ] }, { "name": "Bandwidth.com", "exchanges": 30, "byLineType": { "voip": 30 }, "ranges": [ "225–226", "302", "347", "380", "397", "399", "402–403", "446", "460", "481", "528", "550", "556", "565", "583", "590", "597", "641", "657", "684", "689", "712", "720", "769", "804", "806", "812", "997" ] }, { "name": "Comcast", "exchanges": 17, "byLineType": { "voip": 17 }, "ranges": [ "264", "305", "328", "406", "450", "600", "606", "615", "710", "713", "730", "808", "815", "866", "910", "936", "941" ] }, { "name": "UScellular", "exchanges": 12, "byLineType": { "mobile": 12 }, "ranges": [ "210", "214", "248", "259", "363", "377", "519", "572", "592", "701", "721", "801" ] }, { "name": "Highland Telephone Cooperative", "exchanges": 10, "byLineType": { "fixed_line": 10 }, "ranges": [ "286", "319", "324", "346", "369", "569", "627–628", "663", "965" ] }, { "name": "Spectrum", "exchanges": 10, "byLineType": { "fixed_line": 10 }, "ranges": [ "281", "393", "423", "631", "729", "731", "765", "790", "839", "945" ] }, { "name": "TDS Telecom", "exchanges": 7, "byLineType": { "fixed_line": 7 }, "ranges": [ "253", "261", "295", "462", "568", "884", "887" ] }, { "name": "TELNYX", "exchanges": 7, "byLineType": { "voip": 7 }, "ranges": [ "456", "633", "651", "672", "688", "690", "814" ] }, { "name": "USA Mobility", "exchanges": 7, "byLineType": { "mobile": 7 }, "ranges": [ "221", "409", "412", "469", "514", "655", "795" ] }, { "name": "COMMIO LLC", "exchanges": 6, "byLineType": { "voip": 6 }, "ranges": [ "350", "527", "860", "908", "940", "998" ] }, { "name": "EPB Telecommunications", "exchanges": 6, "byLineType": { "fixed_line": 6 }, "ranges": [ "206", "498", "531", "643", "648", "803" ] }, { "name": "Bledsoe Telephone Cooperative", "exchanges": 5, "byLineType": { "fixed_line": 5 }, "ranges": [ "447", "533", "554", "881", "949" ] }, { "name": "Brightlink Communications", "exchanges": 5, "byLineType": { "mobile": 3, "voip": 2 }, "ranges": [ "430", "524", "602", "705", "719" ] }, { "name": "Fractel", "exchanges": 5, "byLineType": { "voip": 5 }, "ranges": [ "873", "922", "955", "966", "977" ] }, { "name": "Ton80 Communications", "exchanges": 5, "byLineType": { "voip": 5 }, "ranges": [ "832", "925", "927", "932", "934" ] }, { "name": "Emergency Networks", "exchanges": 4, "byLineType": { "mobile": 4 }, "ranges": [ "864", "904–905", "909" ] }, { "name": "BTES", "exchanges": 3, "byLineType": { "fixed_line": 3 }, "ranges": [ "573–575" ] }, { "name": "Dish Wireless", "exchanges": 3, "byLineType": { "mobile": 3 }, "ranges": [ "203", "792", "796" ] }, { "name": "TWIN LAKES COMMUNICATIONS", "exchanges": 3, "byLineType": { "fixed_line": 3 }, "ranges": [ "250", "407", "632" ] }, { "name": "CSC Wireless LLC", "exchanges": 2, "byLineType": { "mobile": 2 }, "ranges": [ "654", "656" ] }, { "name": "HD Carrier", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "993", "995" ] }, { "name": "IP Horizon", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "670–671" ] }, { "name": "Mountainet Telephone Company", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "579", "930" ] }, { "name": "Nuso", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "819", "831" ] }, { "name": "Peerless Network", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "924", "960" ] }, { "name": "Skybest Communications", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "501", "692" ] }, { "name": "Skyetel", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "750", "848" ] }, { "name": "Terra Nova Telecom", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "872", "992" ] }, { "name": "Twilio International", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "660", "853" ] }, { "name": "Vonage", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "541", "549" ] }, { "name": "Wavenation", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "978", "981" ] }, { "name": "Callworks Corporation", "exchanges": 1, "byLineType": { "voip": 1 }, "ranges": [ "906" ] }, { "name": "ETC Communications", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "548" ] }, { "name": "PEACE COMMUNICATIONS", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "414" ] }, { "name": "Pro Page Partners", "exchanges": 1, "byLineType": { "mobile": 1 }, "ranges": [ "233" ] }, { "name": "Scott County Telephone Cooperative", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "944" ] }, { "name": "Skyline Telephone Membership Corporation", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "739" ] }, { "name": "Telescan", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "630" ] } ], "grid": "fffmfvffmfmufmmmfffffmmmfvvmfffmfmfffmffmmffffffmffmfffmffmmmfffvfffmmmmfmffmmffmfffmmfffmmmmmffffffmfvfmvmffmmummmmmfffmfmffffmvmmmfmfmffffmmmffffvffvffffmmfmfmmmmmfmmmfvmfvvvvmfvvmvmmffmmmffffmmfvmvmfvvmmvffmfummfmmfmmfmffffmvfmmfmfffffffmmffmvvfmfvfffffvmmfvfffmmmfvmmmfffmffffmvfmffmfmmfvffmffmffvfmmmmmffvfumfmvffmmfmfmmffvvfmfffmffffmvvffmffffvvvmffuvmvfvvffmvfmfffmmfffmmffmffvmfffmmvvmmvmmvmmvfmvvmvmmmfumffvvmmmmmfffffffffffvfmfmfffvffmmmmffmvfmmmmvffvmvfffvmfvvvvfvvmmvvmmmmvmvmvvvvffmmmffmumfvmvmmmfvuvvfmfmmvvmffffmfffvfmfvfmmmfmmmffffmmmvfffmffffvmfmfffvmfvvvfmmfmvffffffffvffffmmffmmmffmmmfvvvmvffuvmvvmmvfvffmvfff-mvfvmfmmfmfvmfffmffvmvffvffmfvvv-vmm-vfvffmvvfffffvvffffvffvmm-fffmffmfv-mmmmvfvmvumfmf-fmvmfvmvvfvfff-vfv-v-ffvvfmffm-mfumfffvmmuuvf-m-fvmfm--mf-fuvffvf-----m-ffmvvmvmvvm", "patterns": { "all": "^\\+1423[2-9]\\d{6}$", "fixed_line": "^\\+1423(?:2(?:0[0-24679]|1[26-9]|2[0489]|3[024-689]|4[2-79]|5[02-467]|6[1-35-7]|7[24589]|8[1-36-8]|9[4-9])|3(?:0[1378]|1[7-9]|2[13-6]|3[246-9]|4[3-689]|5[1-479]|6[59]|7[28]|8[56]|9[0-36])|4(?:0[178]|1[047]|2[02-58]|3[13-9]|4[2379]|5[1-59]|6[1-37]|7[2-46-9]|8[2457]|9[0235689])|5(?:0[178]|1[0367]|2[02569]|3[1-35-8]|4[235-8]|5[349]|6[23689]|7[03-589]|8[125-7])|6(?:01|1[034]|2[2-9]|3[0-24689]|4[02389]|5[289]|6[3-58]|73|9[2378])|7(?:0[29]|1[46]|2[2-57-9]|3[1359]|4[3-6]|5[1-35-8]|6[13-58]|7[2589]|8[0-57-9]|9[03489])|8(?:0[39]|1[09]|2[125-7]|3[1479]|4[2-467]|5[12457]|6[79]|7[04-8]|8[1-467]|9[2-4679])|9(?:07|1[357]|2[1689]|3[0389]|4[2459]|5[2-4]|6[158]|7[3589]|8[19]|90))\\d{4}$", "mobile": "^\\+1423(?:2(?:0[38]|1[03-5]|2[1-37]|3[137]|4[018]|5[1589]|6[089]|7[01367]|8[0459]|9[0-3])|3(?:0[0469]|1[02-6]|2[0279]|3[0135]|4[0-2]|5[568]|6[0-46-8]|7[17]|8[1347-9]|9[458])|4(?:0[0459]|1[235689]|2[169]|3[02]|4[0148]|5[78]|6[4-69]|7[015]|8[03689]|9[47])|5(?:0[2-6]|1[2489]|2[134]|3[049]|44|5[27]|6[47]|7[1267]|8[0489]|9[235689])|6(?:0[257-9]|1[27-9]|2[01]|3[57]|4[4-7]|5[03-6]|6[17]|7[67]|8[0-357]|9[4-69])|7(?:0[146-8]|1[578]|2[16]|3[26-8]|4[0-27-9]|54|6[027]|7[346]|9[125-7])|8(?:0[0-27]|1[367]|2[39]|3[3568]|4[159]|56|6[34]|71|89|9[058])|9(?:0[2-59]|1[248]|2[03]|4[368]|5[167]|6[379]|72|87|9[1469]))\\d{4}$", "voip": "^\\+1423(?:2(?:05|2[56]|64)|3(?:0[25]|28|47|50|7[03-69]|8[02]|9[79])|4(?:0[236]|27|4[56]|5[06]|6[08]|[89]1)|5(?:0[09]|15|2[78]|4[019]|5[0168]|6[015]|83|9[0147])|6(?:0[0346]|1[56]|33|41|5[17]|6[0269]|7[0-24589]|8[4689]|9[01])|7(?:0[35]|1[0239]|20|3[04]|5[09]|6[69]|7[017]|86)|8(?:0[4-68]|1[2458]|2[04]|3[02]|4[08]|5[0389]|6[0268]|7[239]|8[058])|9(?:0[068]|1[09]|2[2457]|3[246]|4[01]|55|6[06]|77|80|9[23578]))\\d{4}$" }, "sandbox": { "input": "+14235550123", "valid": true, "type": "Fixed line or mobile", "region": "US", "formats": { "e164": "+14235550123", "international": "+1 423-555-0123", "national": "(423) 555-0123", "rfc3966": "tel:+1-423-555-0123" }, "parts": { "countryCode": "+1", "destinationCode": "423", "destinationKind": "area code", "subscriber": "5550123" } }, "faq": [ { "question": "Where is area code 423?", "answer": "Area code 423 is in Tennessee, in the United States: all 779 of its exchanges on record are there. From abroad it is dialled +1 423, then the seven-digit number." }, { "question": "Is a 423 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 779 exchanges on record in 423, 265 (34%) were allocated as mobile, 353 (45%) as fixed line, 147 (19%) 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." }, { "question": "Which carriers have numbers in area code 423?", "answer": "43 carriers hold exchanges in 423 on record; the most: AT&T (216), Lumen (129) and Verizon (84). 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 423 phone number?", "answer": "In E.164 a 423 number matches ^\\+1423[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 (423) 555-0123. The exchange patterns on this page narrow it to the exchanges allocated as mobile, fixed line or VoIP." } ], "neighbours": { "sameRegion": [ "us-615", "us-629", "us-731", "us-865", "us-901", "us-931" ], "previous": "us-419", "next": "us-424" }, "meta": { "dataAsOf": "2026-10-25", "dataPoints": 779, "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" } ] } }