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: 506

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
312-506 A Chicago Zone 01-Franklin IL CHCGIL24DS7  5917 FIRST COMMUNICATIONS, LLC 358      
312-506 0 Chicago Zone 01-Franklin IL CHCGIL24DS7  5917 FIRST COMMUNICATIONS, LLC 358   2004-07-15   
312-506 1 Chicago Zone 01-Franklin IL CHCGIL24DS7  5917 FIRST COMMUNICATIONS, LLC 358   2004-07-15   
312-506 2 Chicago Zone 01-Franklin IL CHCGIL24DS7  5917 FIRST COMMUNICATIONS, LLC 358   2004-07-15   
312-506 3 Chicago Zone 01-Franklin IL CHCGIL24DS7  5917 FIRST COMMUNICATIONS, LLC 358   2004-07-15   
312-506 4 Chicago Zone 01-Franklin IL CHCGILAEDS3  5917 FIRST COMMUNICATIONS, LLC 358   2008-04-03   
312-506 5 Chicago Zone 01-Franklin IL CHCGILWUX1X  4717 PAETEC COMMUNICATIONS, INC. - IL 358   2006-05-20   
312-506 6 Chicago Zone 01-Franklin IL CHCGIL24DS7  5917 FIRST COMMUNICATIONS, LLC 358   2004-07-15   
312-506 7 Chicago Zone 01-Franklin IL CHCGILMF4MD  5562 METROPCS, INC. 358   2005-01-15   
312-506 8 Chicago Zone 01-Franklin IL CHCGILWUX1X  4717 PAETEC COMMUNICATIONS, INC. - IL 358   2006-06-04   
312-506 9 Chicago Zone 01-Franklin IL CHCGIL24DS7  5917 FIRST COMMUNICATIONS, LLC 358   2004-07-15   

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

Sponsored by: VoIP.ms

Like this site? We accept donations via PayPal.