Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 231 [Rate centres in NPA 231] [Dial plan for NPA 231]

NXX: 594

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
231-594 A Hart MI MSKGMIXKRMD  506J TWILIO INTERNATIONAL, INC. 348   2025-01-13   
231-594 0 Hart MI WYNGMIKAGT2  6534 NEW CINGULAR WIRELESS PCS, LLC - IL 348   2023-06-04   
231-594 1 Hart MI MSKGMIXKX1X  543C ONVOY, LLCV - MI 348   2023-08-06   
231-594 2 Hart MI MSKGMIXKRMD  506J TWILIO INTERNATIONAL, INC. 348   2025-01-14   
231-594 3 Hart MI GDRQMIBODS0  7157 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI 348   2012-12-17   
231-594 4 Hart MI MSKGMIXKX1X  543C ONVOY, LLCV - MI 348   2022-05-31   
231-594 5 Hart MI MSKGMIXKX1X  543C ONVOY, LLCV - MI 348   2022-04-17   
231-594 6 Hart MI MSKGMIXKX1X  543C ONVOY, LLCV - MI 348   2017-05-19   
231-594 7 Hart MI MSKGMIXKX1X  543C ONVOY, LLCV - MI 348   2022-05-31   
231-594 8 Hart MI GDRPMIBL31Z  2964 OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 348   2024-03-19   

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

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