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
— 410-424 0XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 GLENBURNIE MD
— 410-425 0XXX1XXX3XXX4XXX7XXX9XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 SMITH IS MD
— 410-426 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-429 0XXX1XXX2XXX3XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 WORTHINGTN MD
— 410-431 0XXX1XXX2XXX3XXX4XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 SEVERNA PK MD
— 410-432 0XXX1XXX2XXX4XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 SEVERNA PK MD
— 410-433 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-435 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-436 0XXX9XXX which blocks → VERIZON MARYLAND, INC. 9212 EDGEWOOD MD
— 410-437 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ARGRGBSNIS MD
— 410-438 0XXX1XXX4XXX6XXX7XXX8XXX · 6 holders which blocks → VERIZON MARYLAND, INC. 9212 SUDLERSVL MD
— 410-439 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ARGRGBSNIS MD
— 410-442 6XXX which blocks → VERIZON MARYLAND, INC. 9212 ELLICOTTCY MD
— 410-444 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-448 8XXX which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-450 3XXX4XXX which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-451 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 CROFTON MD
— 410-452 1XXX2XXX3XXX4XXX6XXX7XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 CARDIFF MD
— 410-453 1XXX2XXX3XXX7XXX8XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-455 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 CATONSVL MD
— 410-457 1XXX3XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → VERIZON MARYLAND, INC. 9212 DARLINGTON MD
— 410-461 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ELLICOTTCY MD
— 410-462 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-464 7XXX8XXX which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-465 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ELLICOTTCY MD
— 410-466 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-467 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-468 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-469 0XXX1XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-471 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ELKRIDGE MD
— 410-472 5XXX8XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 SPARKSGLNC MD
— 410-476 0XXX1XXX2XXX6XXX7XXX8XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 TRAPPE MD
— 410-477 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 SPARROWSPT MD
— 410-479 6XXX7XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 DENTON MD
— 410-480 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ELLICOTTCY MD
— 410-481 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-482 0XXX1XXX3XXX4XXX5XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 GREENSBORO MD
— 410-483 8XXX which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-484 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 PIKESVILLE MD
— 410-485 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-486 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 PIKESVILLE MD
— 410-488 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-489 1XXX3XXX8XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 GLENWOOD MD
— 410-494 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 TOWSON MD
— 410-495 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 PRINCEFRCK MD
— 410-496 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 RANDALLSTN MD
— 410-502 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 BALTIMORE MD
— 410-503 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ELKRIDGE MD
— 410-504 1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 PIKESVILLE MD
— 410-505 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 6 holders which blocks → VERIZON MARYLAND, INC. 9212 ELLICOTTCY 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.