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.

Diamond Bar, CA

<< 1 2 3 >>

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
909-551 9   6529 T-MOBILE USA, INC. 730   2015-03-06   
909-569 A ANHMCA01DS3  7139 TELEPORT COMMUNICATIONS AMERICA, LLC - CA 730      
909-569 0   7139 TELEPORT COMMUNICATIONS AMERICA, LLC - CA 730      
909-569 1   8826 LEVEL 3 COMMUNICATIONS, LLC - CA 730   2001-10-08   
909-569 2   6529 T-MOBILE USA, INC. 730   2003-06-07   
909-569 3   6529 T-MOBILE USA, INC. 730   2004-07-08   
909-569 4   6529 T-MOBILE USA, INC. 730   2004-09-25   
909-569 5   6529 T-MOBILE USA, INC. 730   2004-09-25   
909-569 6   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 730   2004-12-09   
909-569 7   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2005-01-03   
909-569 8   6529 T-MOBILE USA, INC. 730   2005-01-18   
909-569 9   6529 T-MOBILE USA, INC. 730   2005-04-29   
909-594 A WLNTCAXFDS0  2319 FRONTIER CALIFORNIA INC. 730      
909-595 A WLNTCAXFDS0  2319 FRONTIER CALIFORNIA INC. 730      
909-598 A WLNTCAXFDS0  2319 FRONTIER CALIFORNIA INC. 730      
909-610 A IRVECAEIDS2  7240 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA 730      
909-610 0   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2008-08-02   
909-610 1   649C ONVOY, LLC - CA 730   2010-03-07   
909-610 2   7240 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA 730      
909-610 3   649C ONVOY, LLC - CA 730   2008-06-01   
909-610 4   829J PAETEC ITEL, LLC 730   2003-11-10   
909-610 5   6529 T-MOBILE USA, INC. 730   2007-06-24   
909-610 6   8826 LEVEL 3 COMMUNICATIONS, LLC - CA 730   2008-12-08   
909-610 7   6529 T-MOBILE USA, INC. 730   2005-11-05   
909-610 8   8826 LEVEL 3 COMMUNICATIONS, LLC - CA 730   2008-12-08   
909-610 9   981E BANDWIDTH.COM CLEC, LLC - CA 730   2011-06-03   
909-612 A DMBRCAXF86M  2319 FRONTIER CALIFORNIA INC. 730      
909-612 0   2319 FRONTIER CALIFORNIA INC. 730      
909-612 1   2319 FRONTIER CALIFORNIA INC. 730      
909-612 2   2319 FRONTIER CALIFORNIA INC. 730      
909-612 3   7139 TELEPORT COMMUNICATIONS AMERICA, LLC - CA 730      
909-612 4   2319 FRONTIER CALIFORNIA INC. 730      
909-612 5   2319 FRONTIER CALIFORNIA INC. 730      
909-612 6   2319 FRONTIER CALIFORNIA INC. 730      
909-612 7   776C CHARTER FIBERLINK CA-CCO, LLC - CA 730   2005-10-27   
909-612 8   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 730   2001-10-08   
909-612 9   649C ONVOY, LLC - CA 730   2009-04-02   
909-616 A RVSDCALBCM4  6010 NEW CINGULAR WIRELESS PCS, LLC 730      
909-616 0   373F PEERLESS NETWORK OF CALIFORNIA, LLC - CA 730   2019-06-19   
909-616 1   981E BANDWIDTH.COM CLEC, LLC - CA 730   2020-11-14   
909-616 2   624H ONVOY SPECTRUM, LLC 730   2025-02-17   
909-616 3   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 730   2019-12-09   
909-616 4   671J U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 730   2019-04-14   
909-616 5   981E BANDWIDTH.COM CLEC, LLC - CA 730   2020-11-14   
909-616 6   197D VONAGE AMERICA LLC 730   2020-06-23   
909-616 7   197D VONAGE AMERICA LLC 730   2020-06-23   
909-616 8   6529 T-MOBILE USA, INC. 730   2019-01-03   
909-616 9   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2018-11-09   
909-655 A LSANCA039MD  981E BANDWIDTH.COM CLEC, LLC - CA 730      
909-655 0   981E BANDWIDTH.COM CLEC, LLC - CA 730   2015-08-21   
909-655 1   981E BANDWIDTH.COM CLEC, LLC - CA 730   2015-08-21   
909-655 2   671J U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 730   2015-09-28   
909-655 3   7240 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA 730   2015-11-03   
909-655 4   649C ONVOY, LLC - CA 730   2016-03-14   
909-655 5   649C ONVOY, LLC - CA 730   2016-03-14   
909-655 6   576C TIME WARNER CBL INFO SVCS (CA) DBA TIME WARNER CAB 730   2016-04-02   
909-655 7   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2015-12-15   
909-655 8   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2015-10-13   
909-655 9   515J IP HORIZON LLC 730   2015-09-25   
909-718 A IRVNCASM1MD  671J U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 730      
909-718 0   516C AT&T CORP. 730   2026-01-06   
909-718 1   671J U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 730      
909-718 2   981E BANDWIDTH.COM CLEC, LLC - CA 730   2011-06-03   
909-718 3   145J TERRA NOVA TELECOM INC. 730   2025-10-04   
909-718 4   649C ONVOY, LLC - CA 730   2008-07-14   
909-718 5   7139 TELEPORT COMMUNICATIONS AMERICA, LLC - CA 730   2007-03-16   
909-718 6   671J U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 730      
909-718 7   671J U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 730   2007-03-13   
909-718 8   671J U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 730   2007-03-13   
909-718 9   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2009-04-17   
909-760 A COVNCAXFX3Y  649C ONVOY, LLC - CA 730   2024-01-23   
909-760 0   649C ONVOY, LLC - CA 730   2017-06-11   
909-760 1   073H TELNYX LLC 730   2017-06-02   
909-760 2   649C ONVOY, LLC - CA 730   2016-11-09   
909-760 3   649C ONVOY, LLC - CA 730   2016-11-09   
909-760 4   649C ONVOY, LLC - CA 730   2016-11-09   
909-760 5   649C ONVOY, LLC - CA 730   2016-11-09   
909-760 6   649C ONVOY, LLC - CA 730   2016-11-09   
909-760 7   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2017-11-20   
909-760 8   6529 T-MOBILE USA, INC. 730   2018-02-11   
909-760 9   6529 T-MOBILE USA, INC. 730   2016-12-08   
909-839 A WLNTCAXFDS0  2319 FRONTIER CALIFORNIA INC. 730      
909-839 0   2319 FRONTIER CALIFORNIA INC. 730      
909-839 1   2319 FRONTIER CALIFORNIA INC. 730      
909-839 2   2319 FRONTIER CALIFORNIA INC. 730      
909-839 3   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2007-12-08   
909-839 4   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 730   2005-07-23   
909-839 5   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 730   2005-07-23   
909-839 6   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 730   2005-07-23   
909-839 7   2319 FRONTIER CALIFORNIA INC. 730      
909-839 8   2319 FRONTIER CALIFORNIA INC. 730      
909-839 9   508J CENTURYLINK COMMUNICATIONS, LLC 730   2015-07-02   
909-859 A RILTCA11DS0  7480 PACIFIC BELL (COMPETITIVE) 730      
909-859 0   981E BANDWIDTH.COM CLEC, LLC - CA 730   2011-06-03   
909-859 1   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2014-08-08   
909-859 2   7480 PACIFIC BELL (COMPETITIVE) 730      
909-859 3   8826 LEVEL 3 COMMUNICATIONS, LLC - CA 730   2003-04-13   
909-859 4   6529 T-MOBILE USA, INC. 730   2006-10-08   
909-859 5   6529 T-MOBILE USA, INC. 730   2004-01-05   
909-859 6   9262 UTILITY TELECOM GROUP, LLC - CA 730   2006-05-01   

<< 1 2 3 >>

Last updated: Thu, 01 Jan 2026 03:59:49 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.