NumberResearch Membership · Data 09/26/2026

Recent prefix assignments

360 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/26/2026

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, last 30 days
8X8, INC. 43
NEW CINGULAR WIRELESS PCS, LLC - DC 28
ONVOY, LLC - CA 26
NEW CINGULAR WIRELESS PCS, LLC - IL 26
Rogers Communications Canada Inc. (Wireless) 23
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
— 301-519 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD
— 301-520 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 WSHNGTNZN3 MD
— 301-521 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN6 MD
— 301-522 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNGTNZN11 MD
— 301-523 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 301-524 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 FREDERICK MD
— 301-526 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSHNGTNZN3 MD
— 301-527 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD
— 301-528 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD
— 301-529 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSNGTNZN10 MD
— 301-530 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN2 MD
— 301-531 0XXX4XXX5XXX9XXX · 3 holders which blocks → STARPOWER COMMUNICATIONS, LLC - MD 8832 WSHNGTNZN4 MD
— 301-533 5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → VERIZON MARYLAND, INC. 9212 OAKLAND MD
— 301-535 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WALDORF MD
— 301-536 9XXX which blocks → METROPCS, INC. 5562 LEONARDTN MD
— 301-537 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 WSHNGTNZN3 MD
— 301-538 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WSHNGTNZN2 MD
— 301-539 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 LA PLATA MD
— 301-540 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 GAITHERSBG MD
— 301-541 0XXX3XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 WSHNGTNZN5 MD
— 301-542 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 WALDORF MD
— 301-543 0XXX7XXX8XXX9XXX · 2 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 LAUREL236 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
— 301-547 1XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 WSHNGTNZN2 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
— 301-551 not yet reported which blocks → BALTIMORE-WASHINGTON TELEPHONE (BWT) 8697 WSHNGTNZN3 MD
— 301-552 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z13 MD
— 301-553 not yet reported which blocks → SPOK, INC. 6630 WALDORF MD
— 301-554 not yet reported which blocks → SPOK, INC. 6630 WSHNGTNZN2 MD
— 301-555 not yet reported which blocks → MULTIPLE OCN LISTING MULT DIR ASST MD
— 301-556 3XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - DC 7529 GAITHERSBG MD
— 301-559 not yet reported which blocks → VERIZON MARYLAND, INC. 9212 WSHNGTNZN4 MD
— 301-560 not yet reported which blocks → PAETEC ITEL, LLC 829J WSHNGTNZN4 MD
— 301-561 not yet reported which blocks → BALTIMORE-WASHINGTON TELEPHONE (BWT) 8697 WSHNGTNZN3 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
— 301-569 0–9 XXXall 10 · 6 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 GAITHERSBG 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
— 301-573 none assigned yet which blocks → METROPCS, INC. 5562 HAGERSTOWN MD
— 301-574 6XXX7XXX · 2 holders which blocks → VERIZON MARYLAND, INC. 9212 WSNG236Z15 MD
— 301-575 4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → PAETEC ITEL, LLC 829J LAUREL236 MD

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/26/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.