Local Calling Guide

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NPA: 773 [Rate centres in NPA 773] [Dial plan for NPA 773]

NXX: 537

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
773-537 A Chicago Zone 04-Humboldt IL CHCGILWUX6X  460K FIRST COMMUNICATIONS, LLC 358      
773-537 0 Chicago Zone 04-Humboldt IL   460K FIRST COMMUNICATIONS, LLC 358   2004-07-15   
773-537 1 Chicago Zone 04-Humboldt IL   460K FIRST COMMUNICATIONS, LLC 358   2004-07-15   
773-537 2 Chicago Zone 04-Humboldt IL   460K FIRST COMMUNICATIONS, LLC 358   2004-07-15   
773-537 3 Chicago Zone 04-Humboldt IL   460K FIRST COMMUNICATIONS, LLC 358   2004-07-15   
773-537 4 Chicago Zone 04-Humboldt IL   224C ONVOY, LLC 358   2004-09-16   
773-537 5 Chicago Zone 04-Humboldt IL   6529 T-MOBILE USA, INC. 358   2007-01-03   
773-537 6 Chicago Zone 04-Humboldt IL   460K FIRST COMMUNICATIONS, LLC 358   2004-07-15   
773-537 7 Chicago Zone 04-Humboldt IL   460K FIRST COMMUNICATIONS, LLC 358   2004-11-12   
773-537 8 Chicago Zone 04-Humboldt IL   6529 T-MOBILE USA, INC. 358   2005-09-26   
773-537 9 Chicago Zone 04-Humboldt IL   460K FIRST COMMUNICATIONS, LLC 358   2004-07-15   

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

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