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: 274 [Rate centres in NPA 274] [Dial plan for NPA 274]

NXX: 204

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
274-204 A Manitowoc WI MILWWI45XMX  6692 NEW CELL DBA CELLCOM 356   2025-03-14   
274-204 0 Manitowoc WI MILWWI45XMX  6692 NEW CELL DBA CELLCOM 356   2025-03-14   
274-204 1 Manitowoc WI MILXWIJIGT0  6534 NEW CINGULAR WIRELESS PCS, LLC - IL 356   2025-09-28   
274-204 8 Manitowoc WI MILWWIAUDS1  225C ONVOY, LLC - WI 356   2025-10-26   
274-204 9 Manitowoc WI MILXWIILCMD  6508 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WI 356   2026-06-24   

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

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.