Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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San Isidro, TX

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
956-481 A SISDTXXARS0  2159 VALLEY TEL. COOP., INC. 568      
956-671 A HRLNTXHGXFX  508J CENTURYLINK COMMUNICATIONS, LLC 568      
956-671 7 HRLNTXHGXFX  508J CENTURYLINK COMMUNICATIONS, LLC 568   2016-07-09   

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

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