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.
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NPA: 227 [Rate centres in NPA 227] [Dial plan for NPA 227]

NXX: 277

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
227-277 A Gaithersburg MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 236   2025-06-28   
227-277 8 Gaithersburg MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 236   2025-06-28   
227-277 9 Gaithersburg MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 236   2025-06-28   

Last updated: Sun, 01 Jun 2025 02:18:11 UTC

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