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.
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Switch: LARLMDLRDS0

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NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
443-778 4 Waterloo (Washington DC LATA) MD 9212 VERIZON MARYLAND, INC. 236      
443-778 5 Waterloo (Washington DC LATA) MD 9212 VERIZON MARYLAND, INC. 236      
443-778 6 Waterloo (Washington DC LATA) MD 9212 VERIZON MARYLAND, INC. 236      
443-778 7 Waterloo (Washington DC LATA) MD 9212 VERIZON MARYLAND, INC. 236      
443-778 8 Waterloo (Washington DC LATA) MD 9212 VERIZON MARYLAND, INC. 236      
443-778 9 Waterloo (Washington DC LATA) MD 9212 VERIZON MARYLAND, INC. 236   2003-02-15   

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Last updated: Sun, 07 Dec 2025 22:02:11 UTC

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