Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 501 [Rate centres in NPA 501] [Dial plan for NPA 501]

NXX: 578

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
501-578 A Ferndale AR   348F ONVOY, LLC - AR 528   2025-05-04   
501-578 0 Ferndale AR   348F ONVOY, LLC - AR 528   2025-05-04   
501-578 1 Ferndale AR   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 528   2025-07-19   
501-578 2 Ferndale AR   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 528   2025-10-31   
501-578 3 Ferndale AR   348F ONVOY, LLC - AR 528   2026-01-05   
501-578 4 Ferndale AR   515J IP HORIZON LLC 528   2026-06-29   
501-578 5 Ferndale AR   515J IP HORIZON LLC 528   2026-06-29   
501-578 8 Ferndale AR   348F ONVOY, LLC - AR 528   2025-10-26   

Last updated: Tue, 16 Jun 2026 00:09:45 UTC

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