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: 355

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
309-355 A Gridley IL BLTNILXDXPX  846F MEDIACOM TELEPHONY OF ILLINOIS, LLC - IL 366      
309-355 1 Gridley IL BLTNILXDXPX  846F MEDIACOM TELEPHONY OF ILLINOIS, LLC - IL 366   2019-07-12   
309-355 5 Gridley IL   145J TERRA NOVA TELECOM INC. 366   2025-05-27   

Last updated: Sun, 01 Jun 2025 02:18:11 UTC

Sponsored by: Execulink Telecom

Like this site? We accept donations via PayPal.