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: 820 [Rate centres in NPA 820] [Dial plan for NPA 820]

NXX: 241

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
820-241 A Atascadero CA   6529 T-MOBILE USA, INC. 740   2025-06-22   
820-241 0 Atascadero CA   6529 T-MOBILE USA, INC. 740   2025-08-24   
820-241 1 Atascadero CA   6529 T-MOBILE USA, INC. 740   2025-08-24   
820-241 2 Atascadero CA   6529 T-MOBILE USA, INC. 740   2025-10-31   
820-241 3 Atascadero CA   6529 T-MOBILE USA, INC. 740   2025-10-31   
820-241 4 Atascadero CA   6529 T-MOBILE USA, INC. 740   2025-06-29   
820-241 5 Atascadero CA   6529 T-MOBILE USA, INC. 740   2025-06-29   
820-241 6 Atascadero CA   6529 T-MOBILE USA, INC. 740   2025-06-29   
820-241 7 Atascadero CA   6529 T-MOBILE USA, INC. 740   2025-06-29   
820-241 8 Atascadero CA   6529 T-MOBILE USA, INC. 740   2025-06-22   
820-241 9 Atascadero CA   6529 T-MOBILE USA, INC. 740   2025-06-22   

Last updated: Thu, 16 Oct 2025 03:04:18 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.