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: 304 [Rate centres in NPA 304] [Dial plan for NPA 304]

NXX: 677

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
304-677 A Clarksburg WV CLBGWVMARMD  6284 UNITED STATES CELLULAR - WV 256      
304-677 0 Clarksburg WV   6284 UNITED STATES CELLULAR - WV 256      
304-677 1 Clarksburg WV   6284 UNITED STATES CELLULAR - WV 256      
304-677 2 Clarksburg WV   6284 UNITED STATES CELLULAR - WV 256      
304-677 3 Clarksburg WV   6284 UNITED STATES CELLULAR - WV 256      
304-677 4 Clarksburg WV   6284 UNITED STATES CELLULAR - WV 256      
304-677 5 Clarksburg WV   6284 UNITED STATES CELLULAR - WV 256      
304-677 6 Clarksburg WV   6284 UNITED STATES CELLULAR - WV 256      
304-677 7 Clarksburg WV   6284 UNITED STATES CELLULAR - WV 256      
304-677 8 Clarksburg WV   6284 UNITED STATES CELLULAR - WV 256      
304-677 9 Clarksburg WV   6284 UNITED STATES CELLULAR - WV 256      

Last updated: Sat, 02 May 2026 12:20:53 UTC

Sponsored by: VoIP Much Phone Company

Like this site? We accept donations via PayPal.