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: 623 [Rate centres in NPA 623] [Dial plan for NPA 623]

NXX: 955

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
623-955 A Phoenix AZ   907K ALLO COMMUNICATIONS LLC 666   2025-12-19   
623-955 5 Phoenix AZ   907K ALLO COMMUNICATIONS LLC 666   2025-12-19   

Last updated: Thu, 20 Nov 2025 13:34:34 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.