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: CHCGILIDDS0

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
312-222 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-229 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-245 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-321 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-396 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-464 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-527 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-595 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-742 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-744 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-755 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-817 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-822 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-828 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-832 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-836 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-840 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-923 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      
312-970 A Chicago Zone 01-Illinois Dearborn IL 9329 AMERITECH ILLINOIS 358      

Last updated: Sun, 10 Nov 2019 13:49:34 UTC

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