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: 928 [Rate centres in NPA 928] [Dial plan for NPA 928]

NXX: 398

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
928-398 A Somerton AZ PHNXAZ28DS3  630E ONVOY, LLC - AZ 666      
928-398 0 Somerton AZ   6529 T-MOBILE USA, INC. 666   2021-05-07   
928-398 1 Somerton AZ   6529 T-MOBILE USA, INC. 666   2021-05-07   
928-398 2 Somerton AZ   630E ONVOY, LLC - AZ 666   2021-02-05   
928-398 3 Somerton AZ   630E ONVOY, LLC - AZ 666   2021-02-05   
928-398 4 Somerton AZ   6010 NEW CINGULAR WIRELESS PCS, LLC 666   2021-04-13   
928-398 5 Somerton AZ   6010 NEW CINGULAR WIRELESS PCS, LLC 666   2021-04-13   
928-398 6 Somerton AZ   630E ONVOY, LLC - AZ 666   2023-10-14   
928-398 7 Somerton AZ   6529 T-MOBILE USA, INC. 666   2021-02-27   
928-398 8 Somerton AZ   579F PEERLESS NETWORK OF ARIZONA, LLC - AZ 666   2021-02-07   
928-398 9 Somerton AZ   6010 NEW CINGULAR WIRELESS PCS, LLC 666   2021-02-06   

Last updated: Tue, 13 Jan 2026 21:50:02 UTC

Sponsored by: Execulink Telecom

Like this site? We accept donations via PayPal.