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
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Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
— 410-679 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 FORK MD
— 410-680 2XXX3XXX6XXX8XXX · 3 holders which blocks → LEVEL 3 TELECOM OF MARYLAND, LLC - MD 7591 ELLICOTTCY MD
— 410-681 not yet reported which blocks → SPOK, INC. 6630 TOWSON MD
— 410-682 7XXX which blocks → VERIZON MARYLAND, INC. 9212 ESSEX MD
— 410-683 5XXX8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 COCKEYSVL MD
— 410-684 4XXX5XXX8XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-685 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-686 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ESSEX MD
— 410-687 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ESSEX MD
— 410-688 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 FALLSTON MD
— 410-689 5XXX8XXX9XXX · 2 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MD 7325 GLENBURNIE MD
— 410-691 3XXX8XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-692 1XXX3XXX4XXX8XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 JARRETTSVL MD
— 410-693 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 ANNAPOLIS MD
— 410-694 1XXX7XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-695 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 ODENTON MD
— 410-696 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 ELLICOTTCY MD
— 410-697 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 MILLERSVL MD
— 410-698 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 FORK MD
— 410-700 not yet reported which blocks → MD
— 410-701 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 RANDALLSTN MD
— 410-702 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 REISTERSTN MD
— 410-703 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 ANNAPOLIS MD
— 410-704 not yet reported which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 TOWSON MD
— 410-705 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - MD 071F WATERLO236 MD
— 410-706 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-707 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 COLUMBIA MD
— 410-708 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 CHESTERTN MD
— 410-709 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 SPARROWSPT MD
— 410-711 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MD
— 410-712 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ELKRIDGE MD
— 410-713 0–9 XXXall 10 · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 SALISBURY MD
— 410-714 5XXX6XXX7XXX8XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 EASTON MD
— 410-715 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 COLUMBIA MD
— 410-716 4XXX5XXX6XXX8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-717 2XXX3XXX5XXX6XXX8XXX · 2 holders which blocks → LEVEL 3 TELECOM OF MARYLAND, LLC - MD 7591 ELKRIDGE MD
— 410-718 9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 CATONSVL MD
— 410-719 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 CATONSVL MD
— 410-720 2XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 ELLICOTTCY MD
— 410-721 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 CROFTON MD
— 410-722 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WATERLO236 MD
— 410-723 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 OCEAN CITY MD
— 410-724 1XXX8XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WATERLO236 MD
— 410-725 2XXX3XXX5XXX7XXX8XXX which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 EASTON MD
— 410-726 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 SALISBURY MD
— 410-727 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-728 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-729 6XXX which blocks → VERIZON MARYLAND, INC. 9212 SEVERN MD
— 410-730 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 COLUMBIA MD
— 410-731 not yet reported which blocks → SPOK, INC. 6630 ANNAPOLIS 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.