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: 531 [Rate centres in NPA 531] [Dial plan for NPA 531]

NXX: 370

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
531-370 A Fremont NE OMAHNENWXWY  907K ALLO COMMUNICATIONS LLC 644      
531-370 0 Fremont NE OMAHNENWXCY  5807 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - NE 644   2025-05-05   
531-370 1 Fremont NE   549E ONVOY, LLC - NE 644   2026-10-03   
531-370 3 Fremont NE OMAHNENWXMX  6701 AERIAL COMMUNICATIONS, INC. 644   2025-03-19   
531-370 5 Fremont NE OMAHNENWXWY  907K ALLO COMMUNICATIONS LLC 644   2025-01-16   
531-370 7 Fremont NE   883K AHOI LLC 644   2026-09-19   

Last updated: Sat, 10 Oct 2026 15:24:20 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.