Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
  • Effective date searches are available only for US area codes. Our sources for non-US NPA-NXX data do not provide this information.
  • If you want to search an entire area code regardless of activity, leave both the next and past days fields set to zero.

NPA: 774 [Rate centres in NPA 774] [Dial plan for NPA 774]

NXX: 599

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
774-599 A Marlboro MA SOVLMAABAMD  965H FRACTEL, LLC 128      
774-599 0 Marlboro MA   7135 TC SYSTEMS, INC. 128   2026-03-16   
774-599 1 Marlboro MA   7135 TC SYSTEMS, INC. 128   2026-03-16   
774-599 2 Marlboro MA   7135 TC SYSTEMS, INC. 128   2026-03-16   
774-599 5 Marlboro MA CMBRMABENMD  624H ONVOY SPECTRUM, LLC 128   2022-01-27   
774-599 7 Marlboro MA CMBRMABENMD  624H ONVOY SPECTRUM, LLC 128   2022-01-27   
774-599 9 Marlboro MA SOVLMAABAMD  965H FRACTEL, LLC 128   2021-09-17   

Last updated: Sat, 21 Mar 2026 23:53:39 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.