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: 551 [Rate centres in NPA 551] [Dial plan for NPA 551]

NXX: 374

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
551-374 A Dumont NJ NWRKNJMDDSK  637C ONVOY, LLC - NJ 224      
551-374 0 Dumont NJ   490J DISH WIRELESS, LLC 224   2023-07-28   
551-374 1 Dumont NJ   197D VONAGE AMERICA LLC 224   2023-10-13   
551-374 2 Dumont NJ   637C ONVOY, LLC - NJ 224   2023-07-27   
551-374 3 Dumont NJ   637C ONVOY, LLC - NJ 224   2023-07-27   
551-374 4 Dumont NJ   197D VONAGE AMERICA LLC 224   2023-10-13   
551-374 5 Dumont NJ   637C ONVOY, LLC - NJ 224   2024-02-29   
551-374 6 Dumont NJ   4804 LEVEL 3 COMMUNICATIONS, LLC - NJ 224   2024-01-21   
551-374 7 Dumont NJ   637C ONVOY, LLC - NJ 224   2024-02-29   
551-374 8 Dumont NJ   637C ONVOY, LLC - NJ 224   2023-10-21   
551-374 9 Dumont NJ   264F PEERLESS NETWORK OF NEW JERSEY, LLC - NJ 224   2023-08-21   

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.