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 410
VERIZON MARYLAND, INC. 510
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 53
NEW CINGULAR WIRELESS PCS, LLC - DC 51
MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 45
SPOK, INC. 28
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
Clear Download CSV ↓
Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
— 410-836 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BEL AIR MD
— 410-837 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-838 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BEL AIR MD
— 410-839 not yet reported which blocks → SPOK, INC. 6630 TOWSON MD
— 410-840 1XXX6XXX7XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 REISTERSTN MD
— 410-841 0XXX4XXX8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 SEVERNA PK MD
— 410-842 3XXX5XXX7XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 TOWSON MD
— 410-843 not yet reported which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MD 7325 BALTIMORE MD
— 410-846 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 SEVERN MD
— 410-847 0XXX2XXX4XXX5XXX7XXX8XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-848 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WESTMINSTR MD
— 410-849 0XXX1XXX4XXX6XXX7XXX9XXX · 6 holders which blocks → VERIZON MARYLAND, INC. 9212 SHERWD FOR MD
— 410-850 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-851 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-852 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 CATONSVL MD
— 410-853 7XXX which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-854 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WATERLO236 MD
— 410-855 0XXX1XXX2XXX3XXX4XXX5XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-856 1XXX which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-857 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WESTMINSTR MD
— 410-859 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-860 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 SALISBURY MD
— 410-861 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX · 6 holders which blocks → VERIZON MARYLAND, INC. 9212 WESTMINSTR MD
— 410-862 0–9 XXXall 10 · 5 holders which blocks → ONVOY, LLC - MD 876D WATERLO236 MD
— 410-863 2XXX3XXX8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-864 8XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 BALTIMORE MD
— 410-865 0XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-866 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ESSEX MD
— 410-867 5XXX which blocks → VERIZON MARYLAND, INC. 9212 WEST RIVER MD
— 410-868 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 CATONSVL MD
— 410-869 2XXX5XXX6XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 CATONSVL MD
— 410-871 4XXX5XXX8XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 WESTMINSTR MD
— 410-872 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 COLUMBIA MD
— 410-873 0XXX1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 NANTICOKE MD
— 410-874 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 ODENTON MD
— 410-875 7XXX8XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 SYKESVILLE MD
— 410-876 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 REISTERSTN MD
— 410-877 4XXX5XXX6XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 FALLSTON MD
— 410-878 0XXX1XXX2XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 BALTIMORE MD
— 410-879 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 FORK MD
— 410-880 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WATERLO236 MD
— 410-881 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 SHERWD FOR MD
— 410-882 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 PARKVILLE MD
— 410-883 0XXX1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 SHARPTOWN MD
— 410-884 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 COLUMBIA MD
— 410-885 0XXX1XXX4XXX6XXX7XXX8XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 CHESAPKECY MD
— 410-886 0XXX1XXX3XXX6XXX7XXX8XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 TILGHMAN MD
— 410-887 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-888 0XXX2XXX3XXX4XXX6XXX7XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 WATERLO236 MD
— 410-889 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE 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.