Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 650 [Rate centres in NPA 650] [Dial plan for NPA 650]

NXX: 256

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
650-256 A South San Francisco CA SNFCCA21XUY  9748 AMERICAN MESSAGING SERVICES, LLC 722      

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

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