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: 331 [Rate centres in NPA 331] [Dial plan for NPA 331]

NXX: 373

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
331-373 A Oswego IL CHCGILWUTMD  516J TON80 COMMUNICATIONS, LLC 358      
331-373 0 Oswego IL   224C ONVOY, LLC 358   2024-03-01   
331-373 1 Oswego IL   224C ONVOY, LLC 358   2024-03-01   
331-373 2 Oswego IL   224C ONVOY, LLC 358   2024-03-01   
331-373 3 Oswego IL CHCGILWUTMD  516J TON80 COMMUNICATIONS, LLC 358   2022-04-29   
331-373 4 Oswego IL   224C ONVOY, LLC 358   2024-04-05   
331-373 5 Oswego IL CHCGIL24DS6  224C ONVOY, LLC 358   2023-08-12   
331-373 6 Oswego IL CHCGIL24DS6  224C ONVOY, LLC 358   2023-08-12   
331-373 7 Oswego IL CHCGIL24DS6  224C ONVOY, LLC 358   2023-08-12   
331-373 8 Oswego IL CHCGIL24DS6  224C ONVOY, LLC 358   2023-08-12   
331-373 9 Oswego IL CHCGIL24DS6  224C ONVOY, LLC 358   2023-08-12   

Last updated: Fri, 22 Mar 2024 03:02:44 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.