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
— 410-732 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-733 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 CATONSVL MD
— 410-734 2XXX3XXX5XXX8XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 CHURCHVL MD
— 410-735 4XXX6XXX7XXX which blocks → PAETEC ITEL, LLC 829J BALTIMORE MD
— 410-736 0XXX1XXX2XXX3XXX8XXX9XXX which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-737 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ARBUTUS MD
— 410-738 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WATERLO236 MD
— 410-739 7XXX8XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 CENTREVL MD
— 410-740 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 COLUMBIA MD
— 410-741 2XXX3XXX4XXX7XXX8XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 WEST RIVER MD
— 410-742 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 SALISBURY MD
— 410-743 not yet reported which blocks → SPOK, INC. 6630 BALTIMORE MD
— 410-744 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 CATONSVL MD
— 410-745 1XXX7XXX8XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 STMICHAELS MD
— 410-746 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 BALTIMORE MD
— 410-747 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 CATONSVL MD
— 410-748 not yet reported which blocks → SPOK, INC. 6630 ELLICOTTCY MD
— 410-749 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 SALISBURY MD
— 410-750 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ELLICOTTCY MD
— 410-751 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WESTMINSTR MD
— 410-752 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-753 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 PIKESVILLE MD
— 410-754 1XXX4XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 FEDERALSBG MD
— 410-755 0XXX1XXX4XXX5XXX7XXX8XXX9XXX · 6 holders which blocks → VERIZON MARYLAND, INC. 9212 WARWICK MD
— 410-756 0XXX7XXX8XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 TANEYTOWN MD
— 410-757 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ANNAPOLIS MD
— 410-758 none assigned yet which blocks → VERIZON MARYLAND, INC. 9212 CENTREVL MD
— 410-759 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 BALTIMORE MD
— 410-760 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-761 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-762 0XXX2XXX3XXX4XXX7XXX8XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-763 0XXX1XXX2XXX3XXX5XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 EASTON MD
— 410-764 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-765 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-766 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-767 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-768 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-769 0XXX3XXX which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-770 0XXX1XXX2XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 EASTON MD
— 410-771 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 COCKEYSVL MD
— 410-772 4XXX which blocks → VERIZON MARYLAND, INC. 9212 COLUMBIA MD
— 410-773 0XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 COCKEYSVL MD
— 410-774 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 CROFTON MD
— 410-775 3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 UNION BDG MD
— 410-776 0XXX1XXX3XXX4XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MD 7325 BEL AIR MD
— 410-777 0XXX3XXX5XXX6XXX8XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 SEVERNA PK MD
— 410-778 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 CHESTERTN MD
— 410-779 4XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 BALTIMORE MD
— 410-780 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ESSEX MD
— 410-781 1XXX2XXX3XXX5XXX8XXX9XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 ELLICOTTCY 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.