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.

Grimes, CA

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
530-437 A GRMSCAXFRS0  3402 CITIZENS TELECOMM DBA FRONTIER COMM GOLDEN STATE 726      
530-437 0 GRMSCAXFRS0  3402 CITIZENS TELECOMM DBA FRONTIER COMM GOLDEN STATE 726      
530-437 2 GRMSCAXFRS0  3402 CITIZENS TELECOMM DBA FRONTIER COMM GOLDEN STATE 726      
530-437 3 SCRMCA0121Z  671J U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 726   2015-07-17   
530-437 6   145J TERRA NOVA TELECOM INC. 726   2025-05-15   
530-437 7 WSCRCAHW3MD  8826 LEVEL 3 COMMUNICATIONS, LLC - CA 726   2015-03-19   

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

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.