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

NXX: 203

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
227-203 A Frederick MD FRDRMDFRX7X  7228 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 240      
227-203 0 Frederick MD FRDRMDFRXSX  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 240   2023-10-07   
227-203 1 Frederick MD FRDRMDFRX7X  7228 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 240   2023-10-06   
227-203 2 Frederick MD FRDRMDFRX7X  7228 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 240   2023-10-06   
227-203 3 Frederick MD FRDRMDFRX7X  7228 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 240   2023-10-06   
227-203 4 Frederick MD FRDRMDFRXSX  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 240   2023-10-07   
227-203 5 Frederick MD CMLDMDCMUMD  073H TELNYX LLC 240   2024-01-14   
227-203 6 Frederick MD FRDRMDFRXSX  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 240   2024-01-05   
227-203 7 Frederick MD CMLDMDCMEMD  876D ONVOY, LLC - MD 240   2024-09-15   
227-203 8 Frederick MD FRDRMDFRXSX  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 240   2024-08-26   
227-203 9 Frederick MD HGTWMD53DS0  568G PEERLESS NETWORK OF MARYLAND, LLC 240   2023-10-07   

Last updated: Wed, 18 Jun 2025 02:30:00 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.