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: 920 [Rate centres in NPA 920] [Dial plan for NPA 920]

NXX: 556

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
920-556 A Green Bay WI GNBYWI01X9X  9748 AMERICAN MESSAGING SERVICES, LLC 350      

Last updated: Thu, 20 Nov 2025 13:34:34 UTC

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.