Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
  • Effective date searches are available only for US area codes. Our sources for non-US NPA-NXX data do not provide this information.
  • If you want to search an entire area code regardless of activity, leave both the next and past days fields set to zero.

NPA: 406 [Rate centres in NPA 406] [Dial plan for NPA 406]

<< 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 >>

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-437 2 Helena MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2009-07-06   
406-437 3 Helena MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2009-09-14   
406-437 4 Helena MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2011-04-04   
406-437 5 Helena MT   9636 QWEST CORPORATION 648   2008-08-13   
406-437 6 Helena MT   9636 QWEST CORPORATION 648   2008-08-13   
406-437 7 Helena MT   9636 QWEST CORPORATION 648   2008-08-13   
406-437 8 Helena MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2011-07-08   
406-437 9 Helena MT   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 648   2004-09-19   
406-438 A Helena MT HLNAMTMAX1X  6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648      
406-438 0 Helena MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2022-12-10   
406-438 1 Helena MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2009-10-22   
406-438 2 Helena MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2009-10-22   
406-438 3 Helena MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2009-11-23   
406-438 4 Helena MT   9415 LEVEL 3 COMMUNICATIONS, LLC - MT 648   2023-04-01   
406-438 5 Helena MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2010-07-14   
406-438 6 Helena MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2010-10-11   
406-438 7 Helena MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2011-02-06   
406-438 8 Helena MT   073H TELNYX LLC 648   2023-12-09   
406-438 9 Helena MT   073H TELNYX LLC 648   2023-12-09   
406-439 A Helena MT MSSLMTAG5MD  6010 NEW CINGULAR WIRELESS PCS, LLC 648      
406-439 0 Helena MT   6010 NEW CINGULAR WIRELESS PCS, LLC 648      
406-439 1 Helena MT   6010 NEW CINGULAR WIRELESS PCS, LLC 648      
406-439 2 Helena MT   6010 NEW CINGULAR WIRELESS PCS, LLC 648      
406-439 3 Helena MT   6010 NEW CINGULAR WIRELESS PCS, LLC 648      
406-439 4 Helena MT   6010 NEW CINGULAR WIRELESS PCS, LLC 648      
406-439 5 Helena MT   6010 NEW CINGULAR WIRELESS PCS, LLC 648      
406-439 6 Helena MT   6010 NEW CINGULAR WIRELESS PCS, LLC 648      
406-439 7 Helena MT   6010 NEW CINGULAR WIRELESS PCS, LLC 648      
406-439 8 Helena MT   6010 NEW CINGULAR WIRELESS PCS, LLC 648      
406-439 9 Helena MT   6010 NEW CINGULAR WIRELESS PCS, LLC 648      
406-440 A Helena MT HLNAMTHODS1  3924 3 RIVERS TELEPHONE COOPERATIVE, INC. - MT 648      
406-440 0 Helena MT   3924 3 RIVERS TELEPHONE COOPERATIVE, INC. - MT 648      
406-440 1 Helena MT   3924 3 RIVERS TELEPHONE COOPERATIVE, INC. - MT 648      
406-440 2 Helena MT   6010 NEW CINGULAR WIRELESS PCS, LLC 648   2025-09-14   
406-440 3 Helena MT   3924 3 RIVERS TELEPHONE COOPERATIVE, INC. - MT 648      
406-440 4 Helena MT   3924 3 RIVERS TELEPHONE COOPERATIVE, INC. - MT 648      
406-440 5 Helena MT   6529 T-MOBILE USA, INC. 648   2024-02-22   
406-440 6 Helena MT   6529 T-MOBILE USA, INC. 648   2024-02-22   
406-440 7 Helena MT   520K TDS METROCOM, LLC 648   2025-11-17   
406-440 8 Helena MT   3924 3 RIVERS TELEPHONE COOPERATIVE, INC. - MT 648      
406-440 9 Helena MT   3924 3 RIVERS TELEPHONE COOPERATIVE, INC. - MT 648      
406-441 A Helena MT HLNAMTMADS0  9636 QWEST CORPORATION 648      
406-442 A Helena MT HLNAMTMADS0  9636 QWEST CORPORATION 648      
406-443 A Helena MT HLNAMTMADS0  9636 QWEST CORPORATION 648      
406-444 A Helena MT HLNAMTMADS0  9636 QWEST CORPORATION 648      
406-445 A Red Lodge MT RBRTMTMARS1  9636 QWEST CORPORATION 650      
406-445 0 Red Lodge MT   9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650   2004-11-13   
406-445 1 Red Lodge MT   9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650   2007-04-19   
406-445 2 Red Lodge MT   9636 QWEST CORPORATION 650      
406-445 3 Red Lodge MT   792K CHARTER IP ENABLED SERVICES, LLC 650   2011-03-27   

<< 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 >>

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

Sponsored by: BeeVox - Whitelabel Reseller Platform

Like this site? We accept donations via PayPal.