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.

Switch: STLSMOWQ4MD

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
636-630 A O'Fallon MO 939H COMMIO, LLC 520      
636-630 0 O'Fallon MO 939H COMMIO, LLC 520   2022-07-21   

Last updated: Sat, 05 Apr 2025 03:03:23 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.