Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 605 [Rate centres in NPA 605] [Dial plan for NPA 605]

NXX: 636

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
605-636 A Madison SD MDSNSDCERS1  9631 QWEST CORPORATION 640      
605-636 0 Madison SD   9631 QWEST CORPORATION 640      
605-636 1 Madison SD   5180 LEVEL 3 COMMUNICATIONS, LLC - SD 640   2023-01-07   
605-636 2 Madison SD   162G ONVOY, LLC - SD 640   2020-08-21   
605-636 3 Madison SD   162G ONVOY, LLC - SD 640   2012-12-15   
605-636 4 Madison SD   162G ONVOY, LLC - SD 640   2012-12-15   
605-636 5 Madison SD   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 640   2016-11-28   
605-636 6 Madison SD   162G ONVOY, LLC - SD 640   2011-07-05   
605-636 7 Madison SD   162G ONVOY, LLC - SD 640   2009-05-28   
605-636 8 Madison SD   162G ONVOY, LLC - SD 640   2020-08-21   
605-636 9 Madison SD   9631 QWEST CORPORATION 640      

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

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