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: CHCGILFRDS4

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
312-236 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-346 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-364 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-372 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-456 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-462 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-507 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-551 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-580 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-652 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-693 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-704 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-737 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-762 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-782 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-795 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-853 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-931 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      
312-936 A Chicago Zone 01-Franklin IL 9329 AMERITECH ILLINOIS 358      

Last updated: Mon, 24 May 2021 01:28:43 UTC

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