{ "url": "https://phonelookup.dev/prefix/us-531", "npa": "531", "slug": "us-531", "iso": "US", "country": "United States", "regions": [ { "code": "NE", "name": "Nebraska", "exchanges": 283 } ], "exchanges": 283, "known": 265, "byLineType": { "fixed_line": 66, "mobile": 95, "unknown": 18, "voip": 104 }, "carriers": [ { "name": "Onvoy", "exchanges": 64, "byLineType": { "voip": 64 }, "ranges": [ "200–201", "204", "208", "214", "221–223", "227", "230–231", "233–238", "251", "253", "283", "300–301", "317–320", "322–323", "325", "327–328", "331–332", "334", "336–337", "339", "341–342", "351", "353", "360–362", "365–366", "371–372", "395–396", "400", "414", "430", "521", "530", "533–535", "551", "571", "776–777", "810", "910" ] }, { "name": "AT&T", "exchanges": 43, "byLineType": { "fixed_line": 20, "mobile": 23 }, "ranges": [ "217", "219", "232", "241", "243", "245–246", "258", "260–261", "265–266", "277", "282", "288", "290", "296–297", "303–304", "312–313", "338", "348", "401–410", "422–426", "428", "432", "441", "459" ] }, { "name": "Verizon", "exchanges": 29, "byLineType": { "fixed_line": 6, "mobile": 23 }, "ranges": [ "203", "205", "209", "212–213", "216", "224", "228", "240", "242", "250", "259", "262", "279", "291", "321", "329", "335", "354", "358", "363–364", "367", "369", "373", "389", "393", "431", "739" ] }, { "name": "T-Mobile", "exchanges": 26, "byLineType": { "mobile": 26 }, "ranges": [ "210", "218", "229", "239", "248", "263", "270", "272", "281", "292", "294", "326", "344", "346", "349", "374–377", "390–392", "394", "435–436", "625" ] }, { "name": "UScellular", "exchanges": 15, "byLineType": { "mobile": 15 }, "ranges": [ "206", "271", "274–275", "287", "293", "379–382", "384–388" ] }, { "name": "Lumen", "exchanges": 14, "byLineType": { "fixed_line": 11, "voip": 3 }, "ranges": [ "226", "268", "286", "295", "305–307", "314–315", "333", "355", "484", "557", "559" ] }, { "name": "Allo Communications", "exchanges": 9, "byLineType": { "fixed_line": 9 }, "ranges": [ "254", "257", "276", "359", "370", "500", "600", "795", "985" ] }, { "name": "Bandwidth.com", "exchanges": 7, "byLineType": { "voip": 7 }, "ranges": [ "220", "252", "264", "273", "298", "309", "455" ] }, { "name": "COMMIO LLC", "exchanges": 7, "byLineType": { "voip": 7 }, "ranges": [ "302", "310", "330", "340", "343", "357", "867" ] }, { "name": "Comcast", "exchanges": 6, "byLineType": { "voip": 6 }, "ranges": [ "244", "256", "299", "444", "622", "772" ] }, { "name": "Fractel", "exchanges": 5, "byLineType": { "voip": 5 }, "ranges": [ "345", "356", "666", "800", "900" ] }, { "name": "Spectrum", "exchanges": 4, "byLineType": { "fixed_line": 4 }, "ranges": [ "207", "255", "289", "308" ] }, { "name": "TELNYX", "exchanges": 4, "byLineType": { "voip": 4 }, "ranges": [ "202", "215", "278", "888" ] }, { "name": "Ahoi", "exchanges": 3, "byLineType": { "fixed_line": 3 }, "ranges": [ "465", "531", "587" ] }, { "name": "Dish Wireless", "exchanges": 3, "byLineType": { "mobile": 3 }, "ranges": [ "280", "352", "495" ] }, { "name": "Emergency Networks", "exchanges": 3, "byLineType": { "mobile": 3 }, "ranges": [ "368", "510", "710" ] }, { "name": "Nuso", "exchanges": 3, "byLineType": { "fixed_line": 3 }, "ranges": [ "284", "316", "324" ] }, { "name": "Great Plains Broadband", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "721", "727" ] }, { "name": "IP Horizon", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "267", "350" ] }, { "name": "Twilio International", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "893", "895" ] }, { "name": "Vonage", "exchanges": 2, "byLineType": { "voip": 2 }, "ranges": [ "249", "466" ] }, { "name": "Wavenation", "exchanges": 2, "byLineType": { "fixed_line": 2 }, "ranges": [ "427", "434" ] }, { "name": "Access2Go", "exchanges": 1, "byLineType": { "voip": 1 }, "ranges": [ "269" ] }, { "name": "Airus Inc", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "225" ] }, { "name": "CSC Wireless LLC", "exchanges": 1, "byLineType": { "mobile": 1 }, "ranges": [ "247" ] }, { "name": "Cellular One", "exchanges": 1, "byLineType": { "mobile": 1 }, "ranges": [ "519" ] }, { "name": "Glenwood Telecommunications", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "285" ] }, { "name": "Midstates Data Transport", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "438" ] }, { "name": "Terra Nova Telecom", "exchanges": 1, "byLineType": { "voip": 1 }, "ranges": [ "999" ] }, { "name": "Voxtelesys", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "437" ] }, { "name": "Wide Voice", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "541" ] }, { "name": "Wiretap Telecom", "exchanges": 1, "byLineType": { "fixed_line": 1 }, "ranges": [ "433" ] } ], "grid": "vvvmvmmfvmmumfvvfmmfvvvvffvvmmvvmvvvvvvmmfmmvmmmmvmvvvffvfmmmmmmvmmvfvmmmvmmffvmmmmvfffmmfmmmmmfmmvvvvvmmffffvvummfffvvvvmvvfvmvvfvvvvvfvvmvvvvvmvmummvvmvmvvvmfvvvmmvvmmmfvvmmmmmummmmummmmmmmmmfmvv---vffffffffffu--v-------fffffff-vmfffmmff--m--v----------v---m-----fv-----------------f----------m----f---------mu-------m-v--------vf-vvv-----f---------v---u-f-f-----------v---------------f------------f----------u----------v--m----------------------------------------vu--------------------------------u---------mu---------f-----f-----------m--------------------------------v---vv-----------------f----v---------vu-------------------------------------------------------v--------------------v----v-v----v---------vu--------------------------------------u-------uu----------------u--------f-------------v", "patterns": { "all": "^\\+1531[2-9]\\d{6}$", "fixed_line": "^\\+1531(?:2(?:07|1[369]|2[45]|41|5[457]|68|7[67]|8[4-69]|95)|3(?:0[5-8]|1[4-6]|2[49]|35|59|70|93)|4(?:0[1-9]|10|2[2-8]|3[2-478]|65|84)|5(?:00|[34]1|5[79]|87)|600|7(?:2[17]|95)|985)\\d{4}$", "mobile": "^\\+1531(?:2(?:0[3569]|1[0278]|2[89]|3[29]|4[0235-8]|5[089]|6[0-356]|7[0-2459]|8[0-278]|9[0-467])|3(?:0[34]|1[23]|2[16]|38|4[4689]|5[248]|6[347-9]|7[3-79]|8[0-24-9]|9[0-24])|4(?:3[156]|41|59|95)|51[09]|625|7(?:10|39))\\d{4}$", "voip": "^\\+1531(?:2(?:0[0-248]|1[45]|2[0-367]|3[013-8]|4[49]|5[1-36]|6[479]|7[38]|83|9[89])|3(?:0[0-29]|1[07-9]|2[023578]|3[0-4679]|4[0-35]|5[0135-7]|6[0-256]|7[12]|9[56])|4(?:[03]0|[14]4|55|66)|5(?:[257]1|3[03-5])|6(?:22|66)|77[267]|8(?:[01]0|67|88|9[35])|9(?:[01]0|99))\\d{4}$" }, "sandbox": { "input": "+15315550123", "valid": true, "type": "Fixed line or mobile", "region": "US", "formats": { "e164": "+15315550123", "international": "+1 531-555-0123", "national": "(531) 555-0123", "rfc3966": "tel:+1-531-555-0123" }, "parts": { "countryCode": "+1", "destinationCode": "531", "destinationKind": "area code", "subscriber": "5550123" } }, "faq": [ { "question": "Where is area code 531?", "answer": "Area code 531 is in Nebraska, in the United States: all 283 of its exchanges on record are there. From abroad it is dialled +1 531, then the seven-digit number." }, { "question": "Is a 531 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 283 exchanges on record in 531, 95 (34%) were allocated as mobile, 66 (23%) as fixed line, 104 (37%) as VoIP and 18 (6%) 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 531?", "answer": "32 carriers hold exchanges in 531 on record; the most: Onvoy (64), AT&T (43) and Verizon (29). 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 531 phone number?", "answer": "In E.164 a 531 number matches ^\\+1531[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 (531) 555-0123. The exchange patterns on this page narrow it to the exchanges allocated as mobile, fixed line or VoIP." } ], "neighbours": { "sameRegion": [ "us-308", "us-402" ], "previous": "us-530", "next": "us-534" }, "meta": { "dataAsOf": "2026-10-25", "dataPoints": 283, "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" } ] } }