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: 279 [Rate centres in NPA 279] [Dial plan for NPA 279]

NXX: 290

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
279-290 A Elk Grove CA   6529 T-MOBILE USA, INC. 726   2025-12-26   
279-290 0 Elk Grove CA   6010 NEW CINGULAR WIRELESS PCS, LLC 726   2026-02-17   
279-290 1 Elk Grove CA   6010 NEW CINGULAR WIRELESS PCS, LLC 726   2026-02-17   
279-290 5 Elk Grove CA   6529 T-MOBILE USA, INC. 726   2025-12-26   
279-290 6 Elk Grove CA   6529 T-MOBILE USA, INC. 726   2025-12-26   
279-290 7 Elk Grove CA   6529 T-MOBILE USA, INC. 726   2025-12-26   
279-290 8 Elk Grove CA   6529 T-MOBILE USA, INC. 726   2025-12-26   
279-290 9 Elk Grove CA   6529 T-MOBILE USA, INC. 726   2025-12-26   

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

Sponsored by: VoIP Much Phone Company

Like this site? We accept donations via PayPal.