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.

Switch: STMCAZXEPS1

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
435-316 A Monument Valley UT 4451 NAVAJO COMM CO INC - UT DBA NAVAJO COMM UT 981      
505-943 A Shiprock NM 4450 NAVAJO COMM CO INC NM DBA NAVAJO COMM CO NM 664      
928-815 A Window Rock AZ 4449 NAVAJO COMM CO INC - AZ DBA FRONTIER NAVAJO COM 980      

Last updated: Thu, 01 Jan 2026 03:59:49 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.