Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 331 [Rate centres in NPA 331] [Dial plan for NPA 331]

NXX: 304

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
331-304 A Bartlett IL ELGNILOTGT5  6529 T-MOBILE USA, INC. 358      
331-304 0 Bartlett IL   224C ONVOY, LLC 358   2016-03-07   
331-304 1 Bartlett IL   224C ONVOY, LLC 358   2016-03-07   
331-304 2 Bartlett IL   6529 T-MOBILE USA, INC. 358   2017-04-23   
331-304 3 Bartlett IL   6529 T-MOBILE USA, INC. 358   2017-04-23   
331-304 4 Bartlett IL   6529 T-MOBILE USA, INC. 358   2017-04-23   
331-304 5 Bartlett IL   6529 T-MOBILE USA, INC. 358   2017-04-23   
331-304 6 Bartlett IL   063E PEERLESS NETWORK OF ILLINOIS, LLC - IL 358   2020-10-25   
331-304 7 Bartlett IL   6529 T-MOBILE USA, INC. 358   2021-07-24   
331-304 8 Bartlett IL   6529 T-MOBILE USA, INC. 358   2015-04-20   
331-304 9 Bartlett IL   6529 T-MOBILE USA, INC. 358   2015-04-20   

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

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