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: CLMAMDCBRP0

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NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
443-518 1 Columbia MD 9212 VERIZON MARYLAND, INC. 238   2009-03-02   
443-518 2 Columbia MD 9212 VERIZON MARYLAND, INC. 238   2009-03-02   
443-518 3 Columbia MD 9212 VERIZON MARYLAND, INC. 238   2009-03-02   
443-518 4 Columbia MD 9212 VERIZON MARYLAND, INC. 238   2009-03-02   
443-518 5 Columbia MD 9212 VERIZON MARYLAND, INC. 238   2009-03-02   
443-546 A Columbia MD 9212 VERIZON MARYLAND, INC. 238      
443-546 1 Columbia MD 9212 VERIZON MARYLAND, INC. 238      

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Last updated: Sat, 01 Aug 2026 03:19:33 UTC

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