NumberResearch Membership · Data 09/20/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

The Code holder is who opened each NPA-NXX prefix — not necessarily who holds the numbers. A prefix is 10,000 numbers, but under pooling its ten 1,000-number blocks are handed out individually, often to different carriers; the code holder may hold only one block, or none. The Thousands-blocks column shows how the ten blocks are really split — click which blocks → to see who holds each 1,000-number block and its last-4-digit range. Assignments are initial assignments; the current serving carrier may differ due to portability.

Most active assignees, all time — NPA 301
VERIZON MARYLAND, INC. 465
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 51
NEW CINGULAR WIRELESS PCS, LLC - DC 47
MCIMETRO ACCESS TRANSMISSION SERVICES LLC 40
TELEPORT COMMUNICATIONS AMERICA, LLC - DC 31
New assignments by month Sep 2026 Aug 2026 Jul 2026 Jun 2026 May 2026 Apr 2026 Mar 2026 Feb 2026 Jan 2026 Dec 2025 Nov 2025 Oct 2025
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Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
— 301-839 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN6 MD
— 301-840 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-841 3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSHNGTNZN2 MD
— 301-842 4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 CLEAR SPG MD
— 301-843 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN6 MD
— 301-845 3XXX5XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WALKERSVL MD
— 301-846 8XXX which blocks → VERIZON MARYLAND, INC. 9212 FREDERICK MD
— 301-847 9XXX which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN12 MD
— 301-848 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 WALDORF MD
— 301-849 not yet reported which blocks → BANDWIDTH.COM CLEC, LLC - MD 071F OAKLAND MD
— 301-850 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 WSNG236Z14 MD
— 301-851 0XXX1XXX5XXX6XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-852 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-853 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-854 none assigned yet which blocks → VERIZON MARYLAND, INC. 9212 ASHTON238 MD
— 301-855 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG238Z15 MD
— 301-856 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN16 MD
— 301-858 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG238Z14 MD
— 301-860 2XXX7XXX8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z14 MD
— 301-861 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 WALDORF MD
— 301-862 6XXX which blocks → VERIZON MARYLAND, INC. 9212 LXTNPKGRML MD
— 301-863 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 LXTNPKGRML MD
— 301-864 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-865 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 NEW MARKET MD
— 301-866 8XXX which blocks → VERIZON MARYLAND, INC. 9212 LXTNPKGRML MD
— 301-867 1XXX3XXX4XXX5XXX7XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSNG236Z14 MD
— 301-868 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN16 MD
— 301-869 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD
— 301-870 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN6 MD
— 301-871 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN11 MD
— 301-872 1XXX3XXX6XXX7XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 RIDGE MD
— 301-873 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 WSHNGTNZN3 MD
— 301-874 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BUCKEYSTN MD
— 301-875 0–9 XXXall 10 · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 LAUREL236 MD
— 301-877 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN16 MD
— 301-878 not yet reported which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 BALTIMORE MD
— 301-879 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN12 MD
— 301-880 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 LXTNPKGRML MD
— 301-881 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN11 MD
— 301-883 1XXX which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN5 MD
— 301-884 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 MECHANCSVL MD
— 301-885 4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 WALDORF MD
— 301-886 0–9 XXXall 10 · 6 holders which blocks → BANDWIDTH.COM CLEC, LLC - MD 071F WSNG236Z13 MD
— 301-887 3XXX5XXX7XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-888 0XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN16 MD
— 301-889 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNG238Z14 MD
— 301-890 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN12 MD
— 301-891 9XXX which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-893 4XXX5XXX7XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN6 MD
— 301-894 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN6 MD

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.