Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 641 [Rate centres in NPA 641] [Dial plan for NPA 641]

NXX: 422

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
641-422 A Mason City IA MSCYIATCDS0  9631 QWEST CORPORATION 632      

Last updated: Wed, 04 Mar 2026 03:00:52 UTC

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