Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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Duncan, AZ

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
928-359 A PERCAZXCDS0  2176 VALLEY TEL COOP INC 668      
928-439 A TCSNAZMAVMD  3285 LEVEL 3 COMMUNICATIONS, LLC - AZ 668      
928-439 0   939H COMMIO, LLC 668   2022-07-25   
928-439 2   3285 LEVEL 3 COMMUNICATIONS, LLC - AZ 668   2020-07-06   
928-439 4   3285 LEVEL 3 COMMUNICATIONS, LLC - AZ 668   2012-04-29   
928-439 7   516J TON80 COMMUNICATIONS, LLC 668   2022-03-14   
928-439 9   6010 NEW CINGULAR WIRELESS PCS, LLC 668   2015-07-14   

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

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