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.

OCN: 821C INTRADO COMMUNICATIONS, LLC

NPA-NXX BLOCK Rate Centre Region Switch LATA LIR Eff date Disc date
313-616 2 Detroit Zone 1 MI   340   2026-10-15   
313-902 2 Detroit Zone 6 MI   340   2026-10-10   
517-326 7 Lansing MI   346   2026-11-02   
586-587 7 Mount Clemens MI   340   2026-10-05   
810-403 0 Flint MI   340   2026-10-15   
947-278 7 Pontiac MI   340   2026-10-10   
989-272 6 Saginaw MI   344   2026-09-14   
989-320 A Saginaw MI SGNWMIFAXMY  344      
989-320 0 Saginaw MI SGNWMIFAXMY  344   2020-05-22   
989-320 1 Saginaw MI SGNWMIFAXMY  344   2020-05-22   
989-320 7 Saginaw MI   344   2026-09-14   
989-320 8 Saginaw MI SGNWMIFAXMY  344   2020-05-22   
989-320 9 Saginaw MI SGNWMIFAXMY  344   2020-05-22   
989-451 4 Saginaw MI   344   2026-09-14   

Last updated: Tue, 29 Sep 2026 03:00:13 UTC

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