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: 231 [Rate centres in NPA 231] [Dial plan for NPA 231]

NXX: 220

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
231-220 A Muskegon MI GDRPMIBLX8Z  2550 123.NET, LLC 348      
231-220 0 Muskegon MI GDRPMIBLX8Z  2550 123.NET, LLC 348      
231-220 1 Muskegon MI GDRPMIBL31Z  2964 OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 348   2011-03-04   
231-220 2 Muskegon MI GDRPMIBLX8Z  2550 123.NET, LLC 348   2009-11-23   
231-220 3 Muskegon MI GDRPMIBL31Z  2964 OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 348   2011-03-04   
231-220 4 Muskegon MI GDRPMIBL31Z  2964 OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 348   2011-03-04   
231-220 5 Muskegon MI WYNGMIKAGT2  6534 NEW CINGULAR WIRELESS PCS, LLC - IL 348   2006-03-03   
231-220 6 Muskegon MI GDRPMIBL31Z  2964 OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 348   2011-03-04   
231-220 7 Muskegon MI GDRPMIBL31Z  2964 OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 348   2011-03-04   
231-220 8 Muskegon MI GDRPMIBL31Z  2964 OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 348   2011-03-04   
231-220 9 Muskegon MI GDRPMIBL04Z  543C ONVOY, LLCV - MI 348   2015-12-09   

Last updated: Wed, 18 Jun 2025 02:30:00 UTC

Sponsored by: Execulink Telecom

Like this site? We accept donations via PayPal.