Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 508 [Rate centres in NPA 508] [Dial plan for NPA 508]

NXX: 621

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
508-621 A Westboro MA WRCSMA02DS1  7135 TC SYSTEMS, INC. 128      
508-621 0 Westboro MA   7135 TC SYSTEMS, INC. 128      
508-621 1 Westboro MA   7135 TC SYSTEMS, INC. 128      
508-621 2 Westboro MA   7135 TC SYSTEMS, INC. 128      
508-621 3 Westboro MA   7135 TC SYSTEMS, INC. 128      
508-621 4 Westboro MA   7135 TC SYSTEMS, INC. 128      
508-621 5 Westboro MA   7135 TC SYSTEMS, INC. 128      
508-621 6 Westboro MA   892D ONVOY, LLC - MA 128   2010-03-15   
508-621 7 Westboro MA   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 128   2009-03-01   
508-621 8 Westboro MA   892D ONVOY, LLC - MA 128   2010-03-15   
508-621 9 Westboro MA   508J CENTURYLINK COMMUNICATIONS, LLC 128   2014-06-20   

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

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