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: 779 [Rate centres in NPA 779] [Dial plan for NPA 779]

NXX: 421

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
779-421 A Freeport IL   6265 UNITED STATES CELLULAR - IL 360   2025-05-12   
779-421 0 Freeport IL   6265 UNITED STATES CELLULAR - IL 360   2025-05-12   
779-421 1 Freeport IL   6265 UNITED STATES CELLULAR - IL 360   2025-05-12   
779-421 2 Freeport IL   6265 UNITED STATES CELLULAR - IL 360   2025-05-12   
779-421 3 Freeport IL   6265 UNITED STATES CELLULAR - IL 360   2025-05-12   
779-421 4 Freeport IL   6265 UNITED STATES CELLULAR - IL 360   2025-05-12   
779-421 6 Freeport IL   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 360   2026-03-04   
779-421 7 Freeport IL   321J HD CARRIER LLC 360   2026-03-08   
779-421 8 Freeport IL   321J HD CARRIER LLC 360   2026-03-08   
779-421 9 Freeport IL   321J HD CARRIER LLC 360   2026-03-08   

Last updated: Sat, 21 Mar 2026 23:53:39 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.