NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026

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
— 301-409 0–9 XXXall 10 · 2 holders which blocks → ONVOY SPECTRUM, LLC 624H WSHNGTNZN2 MD
— 301-411 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MD
— 301-412 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSHNGTNZN2 MD
— 301-413 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN11 MD
— 301-414 1XXX3XXX4XXX5XXX6XXX8XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 DAMASCS236 MD
— 301-415 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-416 1XXX3XXX5XXX6XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 MYERSVILLE MD
— 301-417 3XXX4XXX5XXX8XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-419 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-420 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN5 MD
— 301-421 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ASHTON236 MD
— 301-422 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-423 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN5 MD
— 301-424 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-425 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-426 6XXX which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-427 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-428 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-429 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-430 1XXX3XXX4XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z14 MD
— 301-431 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-432 none assigned yet which blocks → VERIZON MARYLAND, INC. 9212 KEEDYSVL MD
— 301-433 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN5 MD
— 301-434 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-435 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-436 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-437 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 301-438 4XXX which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN12 MD
— 301-439 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-440 none assigned yet which blocks → METROPCS, INC. 5562 WSHNGTNZN5 MD
— 301-441 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-442 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 301-443 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN11 MD
— 301-444 4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-445 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-446 5XXX which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-447 0XXX4XXX8XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 EMMITSBURG MD
— 301-448 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → COMCAST IP PHONE, LLC 318J WSHNGTNZN3 MD
— 301-449 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN5 MD
— 301-451 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-452 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 WSHNGTNZN3 MD
— 301-453 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 KITZMILLER MD
— 301-454 9XXX which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-455 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 301-456 0XXX3XXX4XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → COMCAST IP PHONE, LLC 318J WSHNGTNZN5 MD
— 301-457 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-458 0XXX1XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 WSHNGTNZN4 MD
— 301-459 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-460 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN11 MD
— 301-461 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 WSNGTNZN10 MD

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.