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
— 301-352 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z14 MD
— 301-353 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-354 6XXX which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 WSNGTNZN10 MD
— 301-356 0–9 XXXall 10 · 2 holders which blocks → VDL, INC. DBA GLOBAL TELECOM BROKERS - MD 4492 LAUREL236 MD
— 301-358 3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 WSNG236Z15 MD
— 301-359 1XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 WESTERNPT MD
— 301-360 5XXX which blocks → VERIZON MARYLAND, INC. 9212 FREDERICK MD
— 301-361 not yet reported which blocks → LEVEL 3 TELECOM OF MARYLAND, LLC - MD 7591 WSHNGTNZN4 MD
— 301-362 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 LAUREL236 MD
— 301-364 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WSHNGTNZN4 MD
— 301-365 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-366 0–9 XXXall 10 · 3 holders which blocks → METROPCS, INC. 5562 GAITHERSBG MD
— 301-367 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 WSHNGTNZN3 MD
— 301-368 0XXX2XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 DAMASCS236 MD
— 301-369 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-370 none assigned yet which blocks → METROPCS, INC. 5562 GAITHERSBG MD
— 301-371 1XXX2XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 MIDDLETOWN MD
— 301-372 4XXX5XXX7XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN16 MD
— 301-373 0XXX1XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 LEONARDTN MD
— 301-374 3XXX4XXX7XXX8XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WALDORF MD
— 301-375 0XXX1XXX2XXX3XXX4XXX5XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 INDIANHEAD MD
— 301-376 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 LAUREL236 MD
— 301-377 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → COMCAST IP PHONE, LLC 318J LAUREL236 MD
— 301-379 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 301-380 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-382 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN11 MD
— 301-383 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → COMCAST IP PHONE, LLC 318J WSNG236Z14 MD
— 301-384 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN12 MD
— 301-385 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSHNGTNZN2 MD
— 301-386 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-387 1XXX which blocks → VERIZON MARYLAND, INC. 9212 OAKLAND MD
— 301-388 5XXX6XXX7XXX8XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN12 MD
— 301-389 2XXX3XXX5XXX6XXX · 2 holders which blocks → LEVEL 3 TELECOM OF MARYLAND, LLC - MD 7591 WSNG236Z13 MD
— 301-390 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z14 MD
— 301-391 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 DAMASCS236 MD
— 301-392 2XXX4XXX7XXX8XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 LA PLATA MD
— 301-393 1XXX6XXX7XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 HAGERSTOWN MD
— 301-394 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-395 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 LAUREL238 MD
— 301-396 2XXX6XXX7XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 WALDORF MD
— 301-397 3XXX7XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-399 none assigned yet which blocks → METROPCS, INC. 5562 WALDORF MD
— 301-401 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 FREDERICK MD
— 301-402 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-403 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-404 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 301-405 not yet reported which blocks → PAETEC ITEL, LLC 829J WSHNGTNZN4 MD
— 301-406 not yet reported which blocks → SPOK, INC. 6630 WSHNGTNZN2 MD
— 301-407 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD
— 301-408 6XXX8XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 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.