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: 831 [Rate centres in NPA 831] [Dial plan for NPA 831]

NXX: 257

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
831-257 A Aptos CA SNFCCAMKDS3  649C ONVOY, LLC - CA 722      
831-257 0 Aptos CA SNFCCAMKDS3  649C ONVOY, LLC - CA 722   2016-11-06   
831-257 1 Aptos CA SNFCCAMKDS3  649C ONVOY, LLC - CA 722   2016-11-06   
831-257 2 Aptos CA SNFCCAMKDS3  649C ONVOY, LLC - CA 722   2016-11-06   
831-257 3 Aptos CA SNFCCAMKDS3  649C ONVOY, LLC - CA 722   2016-11-06   
831-257 4 Aptos CA OKLDCA03XOY  318J COMCAST IP PHONE, LLC 722   2019-09-22   
831-257 5 Aptos CA SNFCCA21XNZ  624H ONVOY SPECTRUM, LLC 722   2020-06-29   
831-257 6 Aptos CA SNFCCA21XNZ  624H ONVOY SPECTRUM, LLC 722   2020-06-29   
831-257 7 Aptos CA SNFCCA21XNZ  624H ONVOY SPECTRUM, LLC 722   2020-06-29   
831-257 8 Aptos CA SNJUCACL3MD  073H TELNYX LLC 722   2017-06-12   
831-257 9 Aptos CA SNFCCA21XNZ  624H ONVOY SPECTRUM, LLC 722   2021-05-24   

Last updated: Tue, 16 Apr 2024 01:38:01 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.