Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 820 [Rate centres in NPA 820] [Dial plan for NPA 820]

NXX: 237

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
820-237 A Atascadero CA SNLOCA01XYX  6529 T-MOBILE USA, INC. 740   2025-02-10   
820-237 0 Atascadero CA SNLOCA01XYX  6529 T-MOBILE USA, INC. 740   2025-11-17   
820-237 1 Atascadero CA   649C ONVOY, LLC - CA 740   2026-07-24   
820-237 2 Atascadero CA SNLOCA01X1Y  6010 NEW CINGULAR WIRELESS PCS, LLC 740   2025-04-27   
820-237 3 Atascadero CA SNLOCA01XYX  6529 T-MOBILE USA, INC. 740   2025-05-25   
820-237 4 Atascadero CA SNLOCA01XYX  6529 T-MOBILE USA, INC. 740   2025-04-05   
820-237 5 Atascadero CA SNLOCA01XYX  6529 T-MOBILE USA, INC. 740   2025-04-05   
820-237 6 Atascadero CA SNLOCA01XYX  6529 T-MOBILE USA, INC. 740   2025-04-05   
820-237 7 Atascadero CA SNLOCA01XYX  6529 T-MOBILE USA, INC. 740   2025-02-23   
820-237 8 Atascadero CA SNLOCA01XYX  6529 T-MOBILE USA, INC. 740   2025-02-23   
820-237 9 Atascadero CA SNLOCA01XYX  6529 T-MOBILE USA, INC. 740   2025-02-10   

Last updated: Sat, 01 Aug 2026 03:19:33 UTC

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