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.

Switch: CHCGILFRDS0

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
312-201 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-220 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-230 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-251 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-267 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-325 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-357 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-368 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-443 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-444 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-541 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-553 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-556 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-557 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-592 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-603 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-606 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-629 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-630 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-641 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-759 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-797 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-812 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-849 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-855 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-857 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-899 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-984 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      

Last updated: Sat, 31 Oct 2020 19:28:10 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.