{ "url": "https://phonelookup.dev/prefix/us-406", "npa": "406", "slug": "us-406", "iso": "US", "country": "United States", "regions": [ { "code": "MT", "name": "Montana", "exchanges": 768 } ], "exchanges": 768, "known": 754, "byLineType": { "fixed_line": 464, "mobile": 213, "unknown": 14, "voip": 77 }, "carriers": [ { "name": "Lumen", "exchanges": 185, "byLineType": { "fixed_line": 180, "voip": 5 }, "ranges": [ "203–206", "213", "222", "225–227", "232–233", "235", "237–238", "243", "245", "247–248", "251–252", "254–259", "262", "265–266", "268", "273", "278", "282", "284–285", "287", "299", "322", "324", "327", "329", "333", "356", "359", "363", "365", "373", "375", "387–389", "413–414", "434", "441–447", "449", "452–455", "457–458", "468", "475–476", "482", "494–497", "504", "507–508", "512", "522–523", "530", "533", "538", "542–543", "545", "548–549", "551–552", "556", "563–565", "574", "578", "582", "585–587", "613", "626", "628", "630", "633", "637", "642", "646", "651–652", "655–657", "659", "662", "665", "668", "683", "686", "693", "721", "723", "727–729", "732", "747–748", "751–752", "755–756", "758", "761", "763", "771", "777", "782", "791", "795", "797", "808", "821", "823", "829", "837–838", "841", "844", "846", "848–849", "854", "857", "862–863", "866", "873", "881", "883–884", "886–888", "892", "896", "900", "902", "924", "933", "943–944", "946", "948", "960–962", "964", "966", "970", "982", "988", "994" ] }, { "name": "Verizon", "exchanges": 123, "byLineType": { "fixed_line": 4, "mobile": 119 }, "ranges": [ "210", "214", "217", "223–224", "230", "249–250", "270", "291", "298", "301", "308", "320", "331", "344", "351", "360–361", "366", "370–371", "380–381", "390", "396", "399", "407–408", "410", "425–426", "431", "437–438", "450", "459", "461", "465", "470–471", "478–481", "490", "498", "517", "521", "529", "531", "544", "546", "558–560", "570", "579", "581", "590–591", "594–595", "598–599", "600", "621", "640–641", "661", "670–672", "690", "694", "696–698", "720", "740", "750", "780–781", "788", "802", "813", "833", "852–853", "865", "868", "871", "876", "880", "885", "909", "913–915", "920", "925", "928", "930–931", "935", "938–939", "941–942", "954–955", "957", "971", "973–975", "977–981", "983", "987" ] }, { "name": "AT&T", "exchanges": 81, "byLineType": { "fixed_line": 7, "mobile": 74 }, "ranges": [ "200–202", "207–209", "212", "220", "229", "231", "239–242", "253", "260–261", "269", "274", "280–281", "289", "303", "305", "314", "321", "334", "340", "350", "369", "382", "391", "417", "439", "460", "489", "491", "499", "505", "514–515", "536", "539", "553", "576", "580", "593", "596–597", "609–610", "617", "625", "660", "691", "699", "743", "749", "790", "799", "815", "818", "824", "850–851", "855", "860–861", "879", "891", "899", "918", "927", "940", "945", "949", "951", "956", "989–990", "997" ] }, { "name": "Sinch (Inteliquent)", "exchanges": 43, "byLineType": { "voip": 43 }, "ranges": [ "221", "272", "290", "302", "306", "313", "316", "318", "341", "403", "405", "412", "416", "418–419", "430", "501", "510", "518", "540", "577", "612", "614", "616", "629", "631", "634", "643", "645", "692", "792", "794", "800", "804", "807", "812", "820", "836", "840", "905", "929", "991–992" ] }, { "name": "Mid-Rivers Telephone Cooperative", "exchanges": 36, "byLineType": { "fixed_line": 36 }, "ranges": [ "234", "323", "345", "354", "358", "377", "428–429", "433", "464", "485–486", "488", "525", "535", "557", "568", "575", "583–584", "588", "635–636", "687", "742", "772–776", "778", "796", "798", "856", "874", "947" ] }, { "name": "Nemont Telephone Cooperative", "exchanges": 33, "byLineType": { "fixed_line": 33 }, "ranges": [ "228", "286", "364", "367", "385", "392", "448", "474", "483", "487", "524", "526–527", "648", "653", "695", "724–725", "746", "762", "765–766", "768–769", "779", "783", "785–787", "789", "893", "895", "963" ] }, { "name": "3 Rivers Telephone Cooperative", "exchanges": 30, "byLineType": { "fixed_line": 30 }, "ranges": [ "216", "236", "264", "271", "276–277", "279", "424", "440", "463", "466–467", "469", "472", "562", "627", "682", "684–685", "733–736", "738", "753", "835", "842–843", "993", "995" ] }, { "name": "Spectrum", "exchanges": 26, "byLineType": { "fixed_line": 26 }, "ranges": [ "300", "307", "309", "319", "330", "393", "404", "415", "420", "422", "493", "502", "513", "534", "571", "702", "709", "730", "830", "839", "845", "890", "897–898", "926", "996" ] }, { "name": "Triangle Telephone Cooperative Association", "exchanges": 26, "byLineType": { "fixed_line": 26 }, "ranges": [ "292", "326", "352", "355", "357", "372", "376", "378–379", "386", "394–395", "397–398", "456", "462", "537", "658", "663", "667", "669", "673–674", "739", "759", "932" ] }, { "name": "Blackfoot Telephone Cooperative", "exchanges": 22, "byLineType": { "fixed_line": 22 }, "ranges": [ "244", "246", "288", "332", "349", "492", "644", "649", "677–678", "722", "726", "745", "754", "793", "822", "825–827", "847", "859", "864" ] }, { "name": "Central Montana Communications", "exchanges": 13, "byLineType": { "fixed_line": 13 }, "ranges": [ "353", "374", "383", "423", "473", "547", "566–567", "572", "622", "632", "654", "737" ] }, { "name": "Range Telephone Cooperative", "exchanges": 13, "byLineType": { "fixed_line": 13 }, "ranges": [ "342", "346–347", "421", "427", "436", "477", "554", "592", "757", "784", "828", "984" ] }, { "name": "Project Telephone Company", "exchanges": 9, "byLineType": { "fixed_line": 9 }, "ranges": [ "328", "343", "348", "638–639", "664", "666", "875", "967" ] }, { "name": "Blackfoot Communications", "exchanges": 8, "byLineType": { "fixed_line": 8 }, "ranges": [ "310", "532", "541", "601–604", "607" ] }, { "name": "Sagebrush Cellular", "exchanges": 7, "byLineType": { "mobile": 7 }, "ranges": [ "263", "315", "620", "650", "680", "688", "953" ] }, { "name": "T-Mobile", "exchanges": 7, "byLineType": { "mobile": 7 }, "ranges": [ "218", "304", "402", "451", "561", "589", "916" ] }, { "name": "Northern Telephone Cooperative", "exchanges": 6, "byLineType": { "fixed_line": 6 }, "ranges": [ "335–337", "339", "432", "937" ] }, { "name": "Southern Montana Telephone Company", "exchanges": 5, "byLineType": { "fixed_line": 5 }, "ranges": [ "267", "681", "689", "832", "834" ] }, { "name": "Allstream", "exchanges": 4, "byLineType": { "fixed_line": 4 }, "ranges": [ "294", "384", "869", "922" ] }, { "name": "Bandwidth.com", "exchanges": 4, "byLineType": { "voip": 4 }, "ranges": [ "219", "647", "870", "936" ] }, { "name": "Frontier", "exchanges": 4, "byLineType": { "fixed_line": 4 }, "ranges": [ "283", "293", "295–296" ] }, { "name": "Nuso", "exchanges": 4, "byLineType": { "fixed_line": 4 }, "ranges": [ "325", "550", "679", "878" ] }, { "name": "Ronan Telephone Company", "exchanges": 4, "byLineType": { "fixed_line": 4 }, "ranges": [ "275", "528", "675–676" ] }, { "name": "TELNYX", "exchanges": 4, "byLineType": { "voip": 4 }, "ranges": [ "317", "605", "703", "831" ] }, { "name": "COMMIO LLC", "exchanges": 3, "byLineType": { "voip": 3 }, "ranges": [ "623", "894", "923" ] }, { "name": "HD Carrier", "exchanges": 3, "byLineType": { "voip": 3 }, "ranges": [ "506", "520", "968" ] }, { "name": "Interbel Telephone Cooperative", "exchanges": 3, "byLineType": { "fixed_line": 3 }, "ranges": [ "297", "882", "889" ] }, { "name": "WEST MT COMMUNITY", "exchanges": 3, "byLineType": { "fixed_line": 3 }, "ranges": [ "615", "744", "872" ] }, { "name": "Airus Inc", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "965", "998" ] }, { "name": "CSC Wireless LLC", "exchanges": 2, "byLineType": { "mobile": 2 }, "ranges": [ "401", "409" ] }, { "name": "Comcast", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "503", "770" ] }, { "name": "Dish Wireless", "exchanges": 2, "byLineType": { "mobile": 2 }, "ranges": [ "516", "858" ] }, { "name": "Emergency Networks", "exchanges": 2, "byLineType": { "mobile": 2 }, "ranges": [ "901", "952" ] }, { "name": "IP Horizon", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "519", "608" ] }, { "name": "Lincoln Telephone Company", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "362", "368" ] }, { "name": "Montana Opticom", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "624", "999" ] }, { "name": "Reservation Telephone Cooperative", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "569", "877" ] }, { "name": "Siyeh Communications", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "338", "573" ] }, { "name": "Skyetel", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "215", "969" ] }, { "name": "TCT WEST", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "484", "764" ] }, { "name": "Tds Metrocom", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "435", "618" ] }, { "name": "Terra Nova Telecom", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "707", "919" ] }, { "name": "Twilio International", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "718–719" ] }, { "name": "Vonage", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "717", "760" ] }, { "name": "Wavenation", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "731", "867" ] }, { "name": "Wide Voice", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "708", "934" ] }, { "name": "Brightlink Communications", "exchanges": 1, "byLineType": { "voip": 1 }, "ranges": [ "312" ] }, { "name": "Exiant", "exchanges": 1, "byLineType": { "voip": 1 }, "ranges": [ "509" ] }, { "name": "Fractel", "exchanges": 1, "byLineType": { "voip": 1 }, "ranges": [ "500" ] }, { "name": "Hot Springs Telephone Company", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "741" ] }, { "name": "Livewire Telecom", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "406" ] }, { "name": "RT Communications", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "767" ] }, { "name": "TRI TEL", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "606" ] }, { "name": "Triangle Communication System", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "400" ] }, { "name": "West River Cooperative Telephone Company", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "972" ] } ], "grid": "fmmffffmmmmumfmvfmmvmvfmmffffmmmfffffffmmmmffffffmmffmffffffmmfmfffffmmfvfffffffmffffffffmvmffffffmffmvfmmvfmffuvvmmvvvfmmfffffffffmffmfffffmvffmfffffmmffffffffmmffffmffmmfffffffffmmmffffffvmmffffmffmfmmvfvfmmmmuvfffvmvvfffffmmfffvmffffffmmffffffffffmmfffffffmmmfffmffffmmffffffmmmmfffffffmmmffffffmmvvfvfmvffvvuffmmmmvvvmfffffffmfmffffmffmvfffmfmffffffmfufffmmmffffffffmfffffmvfmmmfffffffmmmfmmmmmmmmffffvffvmmuvvvfvmf-mmfvfffffvfvffvfffffmmfvfvfvffmfffffffffmmffffffffmmmfffffffmfffffffmfmmvfmfmmmmu-fv---vff-u-----vvvmffffffffvffffffffffmffmfffffmmfffffffffvfffffffffvfffffffffmmffffffmfmfvfvffffmv-m-v--vv--uvf-f--m-vfffmffffffvfmffvfffvfffffffffmmmmfmffmfmmfffmffmfvmffffmffmmffffmfffffmffvffffmfmf--v---m-u-mmmm-mvm-fvfmfmmvmmfffmvfmmmmmffmfffmummmmmmmuuffffffffvvvmfmmmummmmmfmf--mfmmvvfffffff", "patterns": { "all": "^\\+1406[2-9]\\d{6}$", "fixed_line": "^\\+1406(?:2(?:0[03-6]|1[36]|2[25-8]|3[2-8]|4[3-8]|5[124-9]|6[24-8]|7[13-9]|8[1-8]|9[2-79])|3(?:0[0379]|1[09]|[25][2-9]|3[0235-9]|4[235-9]|[69][2-578]|7[1-9]|8[3-8])|4(?:0[046]|1[3-5]|2[0-47-9]|[379][2-7]|4\\d|[58][2-8]|6[2-46-9])|5(?:0[2478]|1[23]|[28][2-8]|3[02-578]|4[1-357-9]|5[0-246-8]|6[2-9]|7[1-58]|92)|6(?:0[1-467]|1[58]|2[24-8]|3[0235-9]|4[24689]|5[1-9]|6[2-9]|7[3-9]|8[1-79]|9[35])|7(?:0[289]|2[1-8]|3\\d|4[124-8]|[5-7][1-9]|8[2-79]|9[135-8])|8(?:1[35]|2[1-35-9]|3[02457-9]|4[1-9]|5[4679]|6[2-4679]|7[2-578]|8[1-46-9]|9[0235-8])|9(?:0[02]|2[246]|3[2-47]|4[346-8]|6[0-7]|72|8[248]|9[3-9]))\\d{4}$", "mobile": "^\\+1406(?:2(?:0[127-9]|1[02478]|2[0349]|3[019]|4[0-29]|5[03]|6[0139]|70|8[09]|9[18])|3(?:0[1458]|1[45]|[25][01]|3[14]|4[04]|[69][0169]|70|8[0-2])|4(?:0[127-9]|1[07]|2[56]|3[189]|[58][019]|6[015]|[79][0189])|5(?:05|1[4-7]|2[19]|3[169]|4[46]|5[39]|6[01]|7[069]|8[019]|9[013-9])|6(?:0[09]|1[07]|[246][01]|50|7[0-2]|8[08]|9[0146-9])|7(?:[25]0|4[039]|8[018]|9[09])|8(?:02|18|24|33|5[0-358]|6[0158]|7[169]|8[05]|9[19])|9(?:0[19]|1[3-68]|2[0578]|3[01589]|4[0-259]|5[1-7]|7[13-57-9]|8[01379]|90))\\d{4}$", "voip": "^\\+1406(?:2(?:1[59]|21|72|90)|3(?:0[26]|1[236-8]|41|89)|4(?:0[35]|1[2689]|30)|5(?:0[01369]|1[089]|[24]0|77)|6(?:0[58]|1[2-46]|2[39]|3[14]|4[357]|92)|7(?:0[37]|1[7-9]|29|[67]0|9[24])|8(?:0[0478]|12|[247]0|3[16]|94)|9(?:05|19|2[39]|36|6[89]|70|9[12]))\\d{4}$" }, "sandbox": { "input": "+14065550123", "valid": true, "type": "Fixed line or mobile", "region": "US", "formats": { "e164": "+14065550123", "international": "+1 406-555-0123", "national": "(406) 555-0123", "rfc3966": "tel:+1-406-555-0123" }, "parts": { "countryCode": "+1", "destinationCode": "406", "destinationKind": "area code", "subscriber": "5550123" } }, "faq": [ { "question": "Where is area code 406?", "answer": "Area code 406 is in Montana, in the United States: all 768 of its exchanges on record are there. From abroad it is dialled +1 406, then the seven-digit number." }, { "question": "Is a 406 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 768 exchanges on record in 406, 213 (28%) were allocated as mobile, 464 (60%) as fixed line, 77 (10%) 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 406?", "answer": "55 carriers hold exchanges in 406 on record; the most: Lumen (185), Verizon (123) and AT&T (81). 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 406 phone number?", "answer": "In E.164 a 406 number matches ^\\+1406[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 (406) 555-0123. The exchange patterns on this page narrow it to the exchanges allocated as mobile, fixed line or VoIP." } ], "neighbours": { "sameRegion": [], "previous": "us-405", "next": "us-407" }, "meta": { "dataAsOf": "2026-10-25", "dataPoints": 768, "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" } ] } }