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: 309 [Rate centres in NPA 309] [Dial plan for NPA 309]

NXX: 971

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
309-971 A Monmouth IL   732J NUSO, LLC 977   2025-05-26   
309-971 1 Monmouth IL   732J NUSO, LLC 977   2025-05-26   

Last updated: Fri, 25 Jul 2025 03:21:23 UTC

Sponsored by: VoIP.ms

Like this site? We accept donations via PayPal.