{ "url": "https://phonelookup.dev/prefix/us-310", "npa": "310", "slug": "us-310", "iso": "US", "country": "United States", "regions": [ { "code": "CA", "name": "California", "exchanges": 800 } ], "exchanges": 800, "known": 787, "byLineType": { "fixed_line": 523, "mobile": 237, "unknown": 13, "voip": 27 }, "carriers": [ { "name": "AT&T", "exchanges": 344, "byLineType": { "fixed_line": 276, "mobile": 68 }, "ranges": [ "200–205", "210", "212", "215–217", "219", "221–226", "228–229", "233", "237", "241–248", "251–253", "255", "257–259", "263", "266", "270–271", "273–289", "291–293", "297", "303", "308–309", "320", "322–338", "340–344", "347–349", "352–355", "357–358", "360", "363–364", "366", "369", "380–381", "383–385", "407–408", "410", "412", "414", "416–419", "423", "426", "431", "435", "463", "467–468", "480–482", "489", "498", "503", "510", "512–525", "527–539", "547–553", "556–559", "562–563", "565", "567–568", "592", "598", "600–601", "603–609", "614–616", "618", "630–633", "635", "637–649", "652–653", "657", "659–662", "665–666", "668–677", "679–680", "682–683", "687", "689", "694–695", "699", "712", "715", "717", "719", "721", "724–727", "729", "732", "739", "744–745", "748", "753–754", "761–764", "767–769", "771–772", "777", "779", "781–789", "795", "801", "804", "808", "812–817", "830–843", "845", "847", "849", "851", "854–855", "858–860", "865", "869", "871", "874", "880", "884–888", "890–891", "897–898", "900", "908", "918", "923", "926", "938", "940–941", "948", "952", "962", "964–965", "967", "969–970", "972–973", "977–978", "981", "983", "989–990", "993–994" ] }, { "name": "Frontier", "exchanges": 137, "byLineType": { "fixed_line": 137 }, "ranges": [ "206–209", "214", "230–231", "234–235", "260", "264–265", "267–268", "301–302", "305–306", "312–319", "370–379", "390–399", "406", "434", "439–459", "465", "470–479", "540–546", "570–578", "581–582", "584", "586–587", "589", "636", "656", "664", "737", "791–794", "796", "798", "802", "820–829", "866", "889", "899", "914–915", "917", "921", "937", "939", "944", "966", "979", "996", "998" ] }, { "name": "Verizon", "exchanges": 102, "byLineType": { "fixed_line": 46, "mobile": 56 }, "ranges": [ "218", "220", "254", "256", "300", "339", "351", "365", "367", "386–387", "405", "413", "415", "422", "425", "427", "429", "433", "437", "460", "486–488", "490", "492", "502", "507–508", "526", "560", "569", "579", "593", "595–596", "602", "612–613", "617", "625", "650", "693", "697", "701–702", "710", "713", "720", "728", "734–736", "738", "740–741", "743", "749–752", "756", "760", "765", "776", "780", "800", "819", "844", "846", "848", "850", "862", "882", "892–895", "903", "905", "907", "909", "912–913", "922", "928", "945", "953–957", "961", "963", "968", "971", "974–975", "988", "991", "995", "997" ] }, { "name": "T-Mobile", "exchanges": 72, "byLineType": { "mobile": 72 }, "ranges": [ "213", "227", "261", "272", "290", "307", "310", "345–346", "350", "359", "400", "403–404", "420–421", "428", "430", "438", "462", "466", "493", "497", "505", "554", "561", "590", "594", "619", "621", "628–629", "634", "654", "663", "678", "684", "686", "703–704", "709", "714", "722", "757", "766", "770", "774", "809", "863–864", "867", "872", "876–877", "901–902", "910", "920", "924–925", "927", "930", "936", "946–947", "951", "980", "982", "985–987", "999" ] }, { "name": "Lumen", "exchanges": 31, "byLineType": { "fixed_line": 31 }, "ranges": [ "294–295", "299", "356", "382", "401–402", "464", "469", "483", "491", "494", "499", "500", "591", "597", "622", "626", "651", "658", "667", "691–692", "733", "773", "775", "803", "878", "916", "933", "984" ] }, { "name": "Tpx Communications", "exchanges": 24, "byLineType": { "fixed_line": 24 }, "ranges": [ "321", "432", "436", "461", "484", "506", "566", "623", "696", "698", "706–707", "746–747", "755", "806", "818", "856–857", "873", "881", "883", "896", "904" ] }, { "name": "USA Mobility", "exchanges": 24, "byLineType": { "mobile": 24 }, "ranges": [ "232", "236", "238–240", "249–250", "262", "298", "368", "501", "509", "585", "588", "685", "716", "718", "723", "790", "805", "875", "932", "960", "992" ] }, { "name": "Onvoy", "exchanges": 17, "byLineType": { "voip": 17 }, "ranges": [ "304", "361–362", "388", "496", "564", "708", "731", "742", "758–759", "807", "861", "868", "919", "935", "943" ] }, { "name": "Network Services", "exchanges": 6, "byLineType": { "mobile": 6 }, "ranges": [ "296", "610", "624", "655", "797", "852" ] }, { "name": "33 Wireless", "exchanges": 5, "byLineType": { "mobile": 5 }, "ranges": [ "485", "495", "583", "599", "942" ] }, { "name": "American Messaging", "exchanges": 5, "byLineType": { "mobile": 5 }, "ranges": [ "389", "681", "799", "931", "934" ] }, { "name": "Bandwidth.com", "exchanges": 5, "byLineType": { "voip": 5 }, "ranges": [ "730", "810", "853", "870", "879" ] }, { "name": "Utility Telephone", "exchanges": 5, "byLineType": { "fixed_line": 5 }, "ranges": [ "269", "580", "688", "705", "778" ] }, { "name": "IP Horizon", "exchanges": 3, "byLineType": { "voip": 3 }, "ranges": [ "409", "906", "929" ] }, { "name": "North County Communications", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "949", "976" ] }, { "name": "Peerless Network", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "504", "627" ] }, { "name": "Integrated Path Communications", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "620" ] }, { "name": "Paetec Itel", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "424" ] }, { "name": "Shelltel", "exchanges": 1, "byLineType": { "mobile": 1 }, "ranges": [ "690" ] } ], "grid": "mfffffffffmufmfffffffffffffmffffmfffmfmmmffffmfffmmmffffmffmfmmfffmfffffmffffffffffmffffffmmmmffmfmfffffvffmmfmufffffffffffffffffffffffffffmmfffmmmmffmmfffffffmfvvffmfmmffffffffffffffmmfmmvmffffffffffmffmmmffmvfufmfmffmfmmmffffmmmmmfmfmffmfffffffffffffffffffffffmmffmmffffffffffffmffffmmmmmmffmfmvmmffmmmvmffmmfuffffffffffffffffmmffffffffffffffffffffffffmuffffmmmfvffmfmfffffffffffffmfmffmfmfmfmfmffmmfffffffffmummmffmfmfmffmmfvmmffffmfffffffffffffffmfffmmfffffffmffmfffffffffffmffmffmmmfffmfffmffffmummmmfffvmmufmmfmmmfmmmmfffffmvvffffffmmmmvffmffmmfffmfffmvvffffffmfffmfffmfmffmmfffffffffmffffmfmfmfmffmmfvfmvuffffffffffffffffffffffffffffffffffffmmmfmvfffffffvmmmffmvmvmmfmmmmfvmfmfffffffmfmffffmfffmmmfmvfmfmummffffmvmfmmmmmmfvmmmfmvmfmfmmmvffmmmfumffffffuummmmffffmffffffffmffmfmffmmmmmmmmmmmfmfm", "patterns": { "all": "^\\+1310[2-9]\\d{6}$", "fixed_line": "^\\+1310(?:2(?:0[1-9]|1[24-9]|2[0-689]|3[013-57]|4[1-46-8]|5[2-578]|6[03-57-9]|7[013-9]|8[0-24-9]|9[4579])|3(?:0[0-3569]|1[2-9]|[279]\\d|3[0-8]|4[1-389]|5[2-8]|6[03469]|8[0-25])|4(?:0[1267]|1[024679]|2[3-6]|3[24679]|[457]\\d|6[014589]|8[1-4]|9[1249])|5(?:0[067]|1[02-9]|2[0-7]|[347]\\d|5[0-36-9]|6[3568]|8[0-24679]|9[13578])|6(?:0[1-9]|1[568]|2[0236]|3[0-35-9]|4\\d|5[1-36-9]|6[0-2457-9]|7[0-79]|8[0237-9]|9[1-35-8])|7(?:0[5-7]|1[259]|2[4-8]|3[2-7]|4[3467]|5[0-24-6]|6[0-57-9]|7[1-3578]|8[1-9]|9[1-468])|8(?:0[02368]|1[2-9]|[23]\\d|4[0-7]|5[14-9]|6[056]|7[38]|8[13-9]|9[13-689])|9(?:0[0479]|1[4-7]|2[18]|3[379]|4[459]|5[2-7]|6[4-79]|7[0-689]|8[134]|9[68]))\\d{4}$", "mobile": "^\\+1310(?:2(?:00|1[03]|27|3[2689]|4[059]|5[0169]|6[126]|72|83|9[0-368])|3(?:0[78]|10|39|4[04-7]|5[019]|6[578]|8[34679])|4(?:0[03-58]|1[358]|2[0-27-9]|3[01358]|6[2367]|8[05-9]|9[03578])|5(?:0[1-3589]|2[89]|54|6[0-279]|8[358]|9[02469])|6(?:00|1[02-479]|2[14589]|34|5[045]|6[36]|78|8[14-6]|9[049])|7(?:0[1-49]|1[0346-8]|2[0-39]|3[89]|4[01589]|5[37]|66|7[0469]|80|9[0579])|8(?:0[1459]|4[89]|[58][02]|6[2-479]|7[124-7]|9[027])|9(?:0[1-358]|1[0238]|2[02-7]|3[0-2468]|4[0-26-8]|51|6[0-38]|77|8[025-9]|9[0-579]))\\d{4}$", "voip": "^\\+1310(?:3(?:04|6[12]|88)|4(?:09|96)|5[06]4|627|7(?:08|3[01]|42|5[89])|8(?:07|10|53|6[18]|7[09])|9(?:06|[12]9|35|43))\\d{4}$" }, "sandbox": { "input": "+13105550123", "valid": true, "type": "Fixed line or mobile", "region": "US", "formats": { "e164": "+13105550123", "international": "+1 310-555-0123", "national": "(310) 555-0123", "rfc3966": "tel:+1-310-555-0123" }, "parts": { "countryCode": "+1", "destinationCode": "310", "destinationKind": "area code", "subscriber": "5550123" } }, "faq": [ { "question": "Where is area code 310?", "answer": "Area code 310 is in California, in the United States: all 800 of its exchanges on record are there. From abroad it is dialled +1 310, then the seven-digit number." }, { "question": "Is a 310 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 800 exchanges on record in 310, 237 (30%) were allocated as mobile, 523 (65%) as fixed line, 27 (3%) as VoIP and 13 (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 310?", "answer": "19 carriers hold exchanges in 310 on record; the most: AT&T (344), Frontier (137) and Verizon (102). 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 310 phone number?", "answer": "In E.164 a 310 number matches ^\\+1310[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 (310) 555-0123. The exchange patterns on this page narrow it to the exchanges allocated as mobile, fixed line or VoIP." } ], "neighbours": { "sameRegion": [ "us-209", "us-213", "us-279", "us-323", "us-341", "us-350", "us-369", "us-408", "us-415", "us-424", "us-442", "us-510", "us-530", "us-559", "us-562", "us-619", "us-626", "us-628", "us-650", "us-657", "us-661", "us-669", "us-707", "us-714", "us-738", "us-747", "us-760", "us-805", "us-818", "us-820", "us-831", "us-840", "us-858", "us-909", "us-916", "us-925", "us-949", "us-951" ], "previous": "us-309", "next": "us-312" }, "meta": { "dataAsOf": "2026-10-25", "dataPoints": 800, "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" } ] } }