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.

Switch: DNCNOKMADS0

Remotes:

Switch Switch name Switch type
MRLWOKMARS1  MARLOW  5ER 
RSSPOKMARS1  RUSH SPRINGS  5ER 
RYANOKMARS1  RYAN  5ER 
WARKOKMARS1  WAURIKA  5ER 
NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
580-251 A Duncan OK 9533 SOUTHWESTERN BELL 536      
580-252 A Duncan OK 9533 SOUTHWESTERN BELL 536      
580-255 A Duncan OK 9533 SOUTHWESTERN BELL 536      
580-470 A Duncan OK 9533 SOUTHWESTERN BELL 536      
580-475 A Duncan OK 9533 SOUTHWESTERN BELL 536      

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

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