Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 309 [Rate centres in NPA 309] [Dial plan for NPA 309]

NXX: 475

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
309-475 A Saybrook IL SYBKILXDRS0  1015 FRONTIER NORTH, INC. - IL 366      
309-475 1 Saybrook IL   073H TELNYX LLC 366   2020-07-19   
309-475 2 Saybrook IL   1015 FRONTIER NORTH, INC. - IL 366      
309-475 4 Saybrook IL   145J TERRA NOVA TELECOM INC. 366   2022-04-09   
309-475 6 Saybrook IL   1015 FRONTIER NORTH, INC. - IL 366      
309-475 7 Saybrook IL   495J STRATUS NETWORKS 366   2020-10-14   
309-475 8 Saybrook IL   145J TERRA NOVA TELECOM INC. 366   2024-02-10   
309-475 9 Saybrook IL   1015 FRONTIER NORTH, INC. - IL 366      

Last updated: Tue, 13 Jan 2026 21:50:02 UTC

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