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: 331 [Rate centres in NPA 331] [Dial plan for NPA 331]

NXX: 242

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
331-242 A Lombard IL ELGNILOTGT5  6529 T-MOBILE USA, INC. 358      
331-242 0 Lombard IL   6529 T-MOBILE USA, INC. 358   2018-12-16   
331-242 1 Lombard IL   6529 T-MOBILE USA, INC. 358   2018-12-16   
331-242 2 Lombard IL   6529 T-MOBILE USA, INC. 358   2018-12-16   
331-242 3 Lombard IL   6529 T-MOBILE USA, INC. 358   2018-12-16   
331-242 4 Lombard IL   6529 T-MOBILE USA, INC. 358   2018-12-16   
331-242 5 Lombard IL   6529 T-MOBILE USA, INC. 358   2018-12-16   
331-242 6 Lombard IL   6529 T-MOBILE USA, INC. 358   2018-12-16   
331-242 7 Lombard IL   6529 T-MOBILE USA, INC. 358   2018-12-16   
331-242 8 Lombard IL   6529 T-MOBILE USA, INC. 358   2018-12-16   
331-242 9 Lombard IL   6529 T-MOBILE USA, INC. 358   2018-12-16   

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

Sponsored by: BeeVox - Whitelabel Reseller Platform

Like this site? We accept donations via PayPal.