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: 275

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
331-275 A Bartlett IL ELGNILOTGT5  6529 T-MOBILE USA, INC. 358      
331-275 6 Bartlett IL ELGNILOTGT5  6529 T-MOBILE USA, INC. 358   2021-09-17   
331-275 7 Bartlett IL ELGNILOTGT5  6529 T-MOBILE USA, INC. 358   2021-09-17   
331-275 8 Bartlett IL ELGNILOTGT5  6529 T-MOBILE USA, INC. 358   2021-09-17   
331-275 9 Bartlett IL ELGNILOTGT5  6529 T-MOBILE USA, INC. 358   2021-09-17   

Last updated: Tue, 31 Mar 2026 13:56:49 UTC

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