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
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
— 301-528 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD
— 301-530 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-533 5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 OAKLAND MD
— 301-540 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD
— 301-544 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-545 2XXX3XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-548 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-549 0XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 ASHTON236 MD
— 301-552 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-559 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-562 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-563 9XXX which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-564 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-565 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-566 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-567 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN6 MD
— 301-568 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN5 MD
— 301-570 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 ASHTON236 MD
— 301-571 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-572 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-574 6XXX7XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z15 MD
— 301-577 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-578 2XXX3XXX5XXX6XXX7XXX · 3 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-579 0XXX1XXX3XXX4XXX5XXX7XXX8XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 BRANDYWINE MD
— 301-581 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-582 8XXX which blocks → VERIZON MARYLAND, INC. 9212 HAGERSTOWN MD
— 301-583 6XXX which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-585 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-586 2XXX5XXX7XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-587 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-588 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-589 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-590 5XXX which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-592 7XXX which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-593 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-594 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-595 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-596 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 LAUREL238 MD
— 301-598 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN12 MD
— 301-599 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN5 MD
— 301-601 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-603 2XXX3XXX4XXX5XXX6XXX · 4 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN11 MD
— 301-604 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 LAUREL236 MD
— 301-605 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-607 none assigned yet which blocks → VERIZON MARYLAND, INC. 9212 DAMASCS240 MD
— 301-608 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN3 MD
— 301-609 0XXX1XXX2XXX which blocks → VERIZON MARYLAND, INC. 9212 WALDORF MD
— 301-610 3XXX which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN10 MD
— 301-614 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-617 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 LAUREL236 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.