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
— 301-674 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN2 MD
— 301-675 not yet reported which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 301-676 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 FREDERICK MD
— 301-677 not yet reported which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 WSNG236Z14 MD
— 301-678 1XXX3XXX4XXX8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 HANCOCK MD
— 301-679 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 WSNGTNZN12 MD
— 301-680 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-681 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-682 1XXX2XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 FREDERICK MD
— 301-683 4XXX5XXX7XXX8XXX9XXX · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 WSHNGTNZN4 MD
— 301-684 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 INDIANHEAD MD
— 301-685 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 DAMASCS236 MD
— 301-686 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN6 MD
— 301-687 2XXX8XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 FROSTBURG MD
— 301-688 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-689 4XXX which blocks → VERIZON MARYLAND, INC. 9212 FROSTBURG MD
— 301-691 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 POOLESVL MD
— 301-692 5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 WSNGTNZN11 MD
— 301-693 not yet reported which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 FREDERICK MD
— 301-694 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 FREDERICK MD
— 301-695 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 FREDERICK MD
— 301-696 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 FREDERICK MD
— 301-697 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 CUMBERLAND MD
— 301-698 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 FREDERICK MD
— 301-699 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-700 not yet reported which blocks → MD
— 301-701 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - MD 071F WSNG236Z13 MD
— 301-702 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN5 MD
— 301-704 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 WSHNGTNZN3 MD
— 301-705 1XXX which blocks → VERIZON MARYLAND, INC. 9212 WALDORF MD
— 301-706 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 WSHNGTNZN3 MD
— 301-707 none assigned yet which blocks → USCOC OF CUMBERLAND, INC. DBA UNITED STATES CEL MD 4720 CUMBERLAND MD
— 301-708 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 LAUREL238 MD
— 301-711 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MD
— 301-712 0–9 XXXall 10 · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 FREDERICK MD
— 301-713 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-714 8XXX which blocks → VERIZON MARYLAND, INC. 9212 HAGERSTOWN MD
— 301-715 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 WSNG236Z15 MD
— 301-716 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-717 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 WSHNGTNZN3 MD
— 301-718 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-719 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 WSNGTNZN16 MD
— 301-720 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 BRANDYWINE MD
— 301-721 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-722 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 CUMBERLAND MD
— 301-723 0XXX1XXX7XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 CUMBERLAND MD
— 301-724 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 CUMBERLAND MD
— 301-725 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 LAUREL236 MD
— 301-727 not yet reported which blocks → BALTIMORE-WASHINGTON TELEPHONE (BWT) 8697 WSHNGTNZN5 MD
— 301-728 not yet reported which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 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.