Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
  • Effective date searches are available only for US area codes. Our sources for non-US NPA-NXX data do not provide this information.
  • If you want to search an entire area code regardless of activity, leave both the next and past days fields set to zero.

NPA: 661 [Rate centres in NPA 661] [Dial plan for NPA 661]

NXX: 438

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
661-438 A Wasco CA BKFDCA119MD  8826 LEVEL 3 COMMUNICATIONS, LLC - CA 734      
661-438 0 Wasco CA BKFDCA11GMD  649C ONVOY, LLC - CA 734      
661-438 1 Wasco CA BKFDCA11EMD  981E BANDWIDTH.COM CLEC, LLC - CA 734   2010-12-06   
661-438 2 Wasco CA BKFDCA11GMD  649C ONVOY, LLC - CA 734   2010-03-08   
661-438 3 Wasco CA BKFDCA11GMD  649C ONVOY, LLC - CA 734   2014-01-07   
661-438 4 Wasco CA BKFDCAJADS0  7128 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA 734   2005-04-28   
661-438 5 Wasco CA BKFDCA119MD  8826 LEVEL 3 COMMUNICATIONS, LLC - CA 734   2005-07-30   
661-438 6 Wasco CA BKFDCA01X2X  5562 METROPCS, INC. 734   2011-02-07   
661-438 7 Wasco CA BKFDCA01X0X  516C AT&T CORP. 734   2011-06-08   
661-438 8 Wasco CA BKFDCA11EMD  981E BANDWIDTH.COM CLEC, LLC - CA 734   2014-03-27   
661-438 9 Wasco CA BKFDCA018MD  6010 NEW CINGULAR WIRELESS PCS, LLC 734   2014-09-11   

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

Sponsored by: VoIP.ms

Like this site? We accept donations via PayPal.