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: 641 [Rate centres in NPA 641] [Dial plan for NPA 641]

NXX: 255

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
641-255 A Mason City IA DESMIAITX6X  6529 T-MOBILE USA, INC. 632      
641-255 0 Mason City IA DESMIAEA0MD  985E BANDWIDTH.COM CLEC, LLC - IA 632   2022-07-16   
641-255 1 Mason City IA DESMIAEA0MD  985E BANDWIDTH.COM CLEC, LLC - IA 632   2022-08-13   
641-255 2 Mason City IA DESMIAEA0MD  985E BANDWIDTH.COM CLEC, LLC - IA 632   2022-08-15   
641-255 3 Mason City IA DESMIADTFMD  221F ONVOY, LLC - IA 632   2023-08-11   
641-255 4 Mason City IA DESMIADTFMD  221F ONVOY, LLC - IA 632   2023-08-11   
641-255 7 Mason City IA DESMIAITX6X  6529 T-MOBILE USA, INC. 632   2022-06-12   
641-255 9 Mason City IA DESMIAITX6X  6529 T-MOBILE USA, INC. 632   2022-06-12   

Last updated: Wed, 04 Mar 2026 03:00:52 UTC

Sponsored by: VoIP Much Phone Company

Like this site? We accept donations via PayPal.