NumberResearch Membership · Data 09/21/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/21/2026

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
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
— 410-344 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 CHASE MD
— 410-345 0XXX9XXX which blocks → VERIZON MARYLAND, INC. 9212 PIKESVILLE MD
— 410-346 0XXX1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 SILVER RUN MD
— 410-347 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-348 0XXX1XXX3XXX4XXX6XXX7XXX8XXX · 6 holders which blocks → VERIZON MARYLAND, INC. 9212 STILL POND MD
— 410-349 5XXX6XXX7XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 ANNAPOLIS MD
— 410-350 1XXX4XXX5XXX6XXX9XXX which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-352 0XXX1XXX2XXX4XXX6XXX7XXX8XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 BISHOPVL MD
— 410-354 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-355 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-356 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 PIKESVILLE MD
— 410-357 1XXX2XXX3XXX6XXX7XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 PARKTON MD
— 410-358 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-359 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-360 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ARGRGBSNIS MD
— 410-361 0XXX1XXX which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-362 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-363 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 PIKESVILLE MD
— 410-364 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX · 7 holders which blocks → VERIZON MARYLAND, INC. 9212 HILLSBORO MD
— 410-366 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-367 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-368 0XXX which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-372 3XXX5XXX6XXX7XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-374 7XXX which blocks → VERIZON MARYLAND, INC. 9212 HAMPSTEAD MD
— 410-376 1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 VIENNA MD
— 410-377 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-378 7XXX which blocks → VERIZON MARYLAND, INC. 9212 PT DEPOSIT MD
— 410-379 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ELKRIDGE MD
— 410-381 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 COLUMBIA MD
— 410-383 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-384 3XXX4XXX6XXX8XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 SEVERNA PK MD
— 410-385 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-386 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WESTMINSTR MD
— 410-388 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 SPARROWSPT MD
— 410-391 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ESSEX MD
— 410-392 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ELKTON MD
— 410-393 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-394 4XXX5XXX7XXX8XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 SOLOMONS MD
— 410-395 4XXX which blocks → VERIZON MARYLAND, INC. 9212 ARBUTUS MD
— 410-396 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-397 0XXX1XXX5XXX7XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 WINGATE MD
— 410-398 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ELKTON MD
— 410-399 1XXX3XXX5XXX8XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 BEL AIR MD
— 410-405 3XXX6XXX7XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 FORK MD
— 410-407 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ELKRIDGE MD
— 410-414 6XXX which blocks → VERIZON MARYLAND, INC. 9212 PRINCEFRCK MD
— 410-415 1XXX3XXX9XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 PIKESVILLE MD
— 410-418 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ELLICOTTCY MD
— 410-420 4XXX5XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 BEL AIR MD
— 410-421 0XXX1XXX2XXX3XXX4XXX6XXX7XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 SEVERNA PK MD

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/21/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.