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: 975

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
312-975 A Chicago Zone 01-Calumet IL CHCGILMF6MD  6529 T-MOBILE USA, INC. 358      
312-975 0 Chicago Zone 01-Calumet IL CHCGILMF6MD  6529 T-MOBILE USA, INC. 358   2015-07-08   
312-975 1 Chicago Zone 01-Calumet IL CHCGILMF6MD  6529 T-MOBILE USA, INC. 358   2015-07-08   
312-975 2 Chicago Zone 01-Calumet IL CHCGILMF6MD  6529 T-MOBILE USA, INC. 358   2015-07-08   
312-975 3 Chicago Zone 01-Calumet IL CHCGILMF6MD  6529 T-MOBILE USA, INC. 358   2015-07-08   
312-975 4 Chicago Zone 01-Calumet IL CHCGILMF6MD  6529 T-MOBILE USA, INC. 358   2015-07-08   
312-975 5 Chicago Zone 01-Calumet IL CHCGILMF6MD  6529 T-MOBILE USA, INC. 358   2015-07-08   
312-975 6 Chicago Zone 01-Calumet IL CHCGILMF6MD  6529 T-MOBILE USA, INC. 358   2014-11-14   
312-975 7 Chicago Zone 01-Calumet IL CHCGILMF6MD  6529 T-MOBILE USA, INC. 358   2014-11-14   
312-975 8 Chicago Zone 01-Calumet IL CHCGILMF6MD  6529 T-MOBILE USA, INC. 358   2014-11-14   
312-975 9 Chicago Zone 01-Calumet IL CHCGILMF6MD  6529 T-MOBILE USA, INC. 358   2014-11-14   

Last updated: Fri, 22 Mar 2024 03:02:44 UTC

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.