Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 657 [Rate centres in NPA 657] [Dial plan for NPA 657]

NXX: 818

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
657-818 A Cypress CA   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2025-08-01   
657-818 9 Cypress CA   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2025-08-01   

Last updated: Wed, 18 Jun 2025 02:30:00 UTC

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