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: 312 [Rate centres in NPA 312] [Dial plan for NPA 312]

NXX: 579

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
312-579 A Chicago Zone 01-Calumet IL RVDLILBDAMD  6333 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 358      
312-579 0 Chicago Zone 01-Calumet IL CHCGILWUJMD  073H TELNYX LLC 358   2017-09-09   
312-579 1 Chicago Zone 01-Calumet IL OKBRILOAXEX  7136 TELEPORT COMMUNICATIONS AMERICA, LLC - IL 358   2017-11-06   
312-579 2 Chicago Zone 01-Calumet IL CHCGILGMDS7  6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358   2017-09-09   
312-579 3 Chicago Zone 01-Calumet IL CHCGILGMDS7  6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358   2017-09-09   
312-579 4 Chicago Zone 01-Calumet IL CHCGILNEXJX  318J COMCAST IP PHONE, LLC 358   2017-10-27   
312-579 5 Chicago Zone 01-Calumet IL RVDLILBDAMD  6333 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 358   2017-09-08   
312-579 6 Chicago Zone 01-Calumet IL RVDLILBDAMD  6333 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 358   2017-09-08   
312-579 7 Chicago Zone 01-Calumet IL RVDLILBDAMD  6333 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 358   2017-09-08   
312-579 8 Chicago Zone 01-Calumet IL RVDLILBDAMD  6333 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 358   2017-09-08   
312-579 9 Chicago Zone 01-Calumet IL RVDLILBDAMD  6333 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 358   2017-09-08   

Last updated: Tue, 16 Apr 2024 01:38:01 UTC

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.