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: 667 [Rate centres in NPA 667] [Dial plan for NPA 667]

NXX: 537

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
667-537 A Essex MD CLMAMDORAMD  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2026-03-01   
667-537 0 Essex MD   876D ONVOY, LLC - MD 238   2026-08-21   
667-537 1 Essex MD   876D ONVOY, LLC - MD 238   2026-09-19   
667-537 7 Essex MD   071F BANDWIDTH.COM CLEC, LLC - MD 238   2026-11-07   
667-537 8 Essex MD CLMAMDORAMD  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2026-06-12   
667-537 9 Essex MD CLMAMDORAMD  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2026-03-01   

Last updated: Sat, 10 Oct 2026 15:24:20 UTC

Sponsored by: Execulink Telecom

Like this site? We accept donations via PayPal.