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: 837

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
312-837 A Chicago Zone 01-Calumet IL CHCGILNEXJX  318J COMCAST IP PHONE, LLC 358      
312-837 0 Chicago Zone 01-Calumet IL CHCGILWUDS4  063E PEERLESS NETWORK OF ILLINOIS, LLC - IL 358   2015-10-19   
312-837 1 Chicago Zone 01-Calumet IL CHCGILWBXWZ  829J PAETEC ITEL, LLC 358   2015-11-04   
312-837 2 Chicago Zone 01-Calumet IL CHCGILWUX6X  460K FIRST COMMUNICATIONS, LLC 358   2016-06-17   
312-837 3 Chicago Zone 01-Calumet IL CHCGILNEXJX  318J COMCAST IP PHONE, LLC 358   2015-10-18   
312-837 4 Chicago Zone 01-Calumet IL CHCGILWBXWZ  829J PAETEC ITEL, LLC 358   2015-11-04   
312-837 5 Chicago Zone 01-Calumet IL ELGNILOTGT5  5562 METROPCS, INC. 358   2015-10-26   
312-837 6 Chicago Zone 01-Calumet IL ELGNILOTGT5  5562 METROPCS, INC. 358   2015-10-26   
312-837 7 Chicago Zone 01-Calumet IL ELGNILOTGT5  5562 METROPCS, INC. 358   2015-10-26   
312-837 8 Chicago Zone 01-Calumet IL ELGNILOTGT5  5562 METROPCS, INC. 358   2015-10-26   
312-837 9 Chicago Zone 01-Calumet IL BURGILAHGT3  6534 NEW CINGULAR WIRELESS PCS, LLC - IL 358   2015-11-23   

Last updated: Sun, 26 Jan 2025 15:59:20 UTC

Sponsored by: LES.NET

Like this site? We accept donations via PayPal.