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: 203 [Rate centres in NPA 203] [Dial plan for NPA 203]

NXX: 437

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
203-437 A Waterbury CT HRFRCTASDS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 920      
203-437 0 Waterbury CT BLFDCTAP2MD  5562 METROPCS, INC. 920      
203-437 1 Waterbury CT BLFDCTAP2MD  5562 METROPCS, INC. 920      
203-437 2 Waterbury CT MDTWCTNIGT1  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 920      
203-437 3 Waterbury CT HRFRCTASDS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 920      
203-437 4 Waterbury CT SMFRCTPU4MD  4800 LEVEL 3 COMMUNICATIONS, LLC - CT 920      
203-437 5 Waterbury CT MDTWCTNIGT1  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 920      
203-437 6 Waterbury CT SMFRCTPU4MD  4800 LEVEL 3 COMMUNICATIONS, LLC - CT 920      
203-437 7 Waterbury CT SMFRCTPU4MD  4800 LEVEL 3 COMMUNICATIONS, LLC - CT 920      
203-437 8 Waterbury CT HRFRCTCR3MD  318J COMCAST IP PHONE, LLC 920      
203-437 9 Waterbury CT HRFRCTASDS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 920      

Last updated: Wed, 20 Nov 2024 21:20:06 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.