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: SFLDMIMKCMD

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
248-639 5 Pontiac MI 321J HD CARRIER LLC 340   2026-03-27   
248-750 9 Southfield MI 321J HD CARRIER LLC 340   2026-03-27   
248-784 9 Southfield MI 321J HD CARRIER LLC 340   2026-03-27   
313-552 A Detroit Zone 1 MI 321J HD CARRIER LLC 340      
313-552 9 Detroit Zone 1 MI 321J HD CARRIER LLC 340   2020-11-21   
313-620 2 Detroit Zone 3 MI 321J HD CARRIER LLC 340   2025-11-03   
313-732 3 Detroit Zone 2 MI 321J HD CARRIER LLC 340   2025-11-03   
313-734 2 Detroit Zone 1 MI 321J HD CARRIER LLC 340   2026-07-17   
313-734 3 Detroit Zone 1 MI 321J HD CARRIER LLC 340   2026-07-17   
313-734 4 Detroit Zone 1 MI 321J HD CARRIER LLC 340   2026-07-17   
313-857 2 Detroit Zone 6 MI 321J HD CARRIER LLC 340   2025-11-03   
734-251 6 Ann Arbor MI 321J HD CARRIER LLC 340   2025-11-03   
810-353 4 Flint MI 321J HD CARRIER LLC 340   2025-11-03   
810-466 7 Columbiaville MI 321J HD CARRIER LLC 340   2025-11-03   
947-276 4 Pontiac MI 321J HD CARRIER LLC 340   2026-03-27   
947-276 5 Pontiac MI 321J HD CARRIER LLC 340   2026-03-27   
947-281 3 Southfield MI 321J HD CARRIER LLC 340   2026-03-27   

Last updated: Sat, 01 Aug 2026 03:19:33 UTC

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