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.

NPA: 517 [Rate centres in NPA 517] [Dial plan for NPA 517]

NXX: 221

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
517-221 A Holt MI LNNGMIMNX4Z  6534 NEW CINGULAR WIRELESS PCS, LLC - IL 346      
517-221 0 Holt MI   6003 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 346   2016-08-18   
517-221 1 Holt MI   6003 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 346   2016-08-18   
517-221 2 Holt MI   6003 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 346   2016-08-18   
517-221 3 Holt MI   6003 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 346   2016-08-18   
517-221 4 Holt MI   6003 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 346   2016-08-18   
517-221 5 Holt MI   6003 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 346   2016-08-18   
517-221 6 Holt MI   6003 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 346   2016-08-18   
517-221 7 Holt MI   6003 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 346   2016-08-18   
517-221 8 Holt MI   6003 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 346   2016-08-18   
517-221 9 Holt MI   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 346   2016-05-27   

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.