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: DTRTMIBASMD

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
248-516 A Farmington MI 516C AT&T CORP. 340      
313-472 A Detroit Zone 5 MI 516C AT&T CORP. 340      
313-694 A Detroit Zone 5 MI 516C AT&T CORP. 340      
313-740 A Detroit Zone 5 MI 516C AT&T CORP. 340      
313-789 A Detroit Zone 6 MI 516C AT&T CORP. 340      
586-393 A Center Line MI 516C AT&T CORP. 340      
586-434 A Warren MI 516C AT&T CORP. 340      
586-745 A Washington MI 516C AT&T CORP. 340      
734-315 A New Boston MI 516C AT&T CORP. 340      

Last updated: Thu, 01 Jan 2026 03:59:49 UTC

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