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.

Essex, MD

<< 1 2 3 4 5 6

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
667-442 1 BLTMMDCH40Z  6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2023-09-22   
667-442 2 BLTMMDCH40Z  6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2023-09-22   
667-442 3 BLTMMDCH42Z  876D ONVOY, LLC - MD 238   2024-02-25   
667-442 4 BLTMMDCH42Z  876D ONVOY, LLC - MD 238   2024-02-25   
667-442 5 BLTMMDCH40Z  6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2023-11-17   
667-442 6 CLMAMDORAMD  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2025-01-26   
667-442 7 CLMAMDORAMD  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2024-07-29   
667-442 8 BLTMMDCH42Z  876D ONVOY, LLC - MD 238   2024-07-29   
667-442 9 CLMAMDORAMD  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2023-09-16   
667-537 A CLMAMDORAMD  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2026-03-01   
667-537 0   876D ONVOY, LLC - MD 238   2026-08-21   
667-537 8 CLMAMDORAMD  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2026-06-12   
667-537 9 CLMAMDORAMD  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2026-03-01   

<< 1 2 3 4 5 6

Last updated: Sat, 01 Aug 2026 03:19:33 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.