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 817
SOUTHWESTERN BELL 302
NEW CINGULAR WIRELESS PCS, LLC - IL 88
T-MOBILE USA, INC. 54
LEVEL 3 COMMUNICATIONS, LLC - TX 45
ONVOY, LLC - TX 43
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
— 817-455 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - TX 6506 ARLINGTON TX
— 817-456 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - TX 6506 ARLINGTON TX
— 817-457 not yet reported which blocks → SOUTHWESTERN BELL 9533 GLENDALE TX
— 817-458 0–9 XXXall 10 · 7 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J WEATHERFD TX
— 817-459 not yet reported which blocks → SOUTHWESTERN BELL 9533 ARLINGTON TX
— 817-460 9XXX which blocks → SOUTHWESTERN BELL 9533 ARLINGTON TX
— 817-461 not yet reported which blocks → SOUTHWESTERN BELL 9533 ARLINGTON TX
— 817-462 not yet reported which blocks → SOUTHWESTERN BELL 9533 ARLINGTON TX
— 817-463 not yet reported which blocks → GRANDE COMMUNICATIONS NETWORKS, INC. - TX 7670 FORT WORTH TX
— 817-464 8XXX which blocks → GRANDE COMMUNICATIONS NETWORKS, INC. - TX 7670 ROANOKE TX
— 817-465 not yet reported which blocks → SOUTHWESTERN BELL 9533 ARLINGTON TX
— 817-466 6XXX which blocks → SOUTHWESTERN BELL 9533 ARLINGTON TX
— 817-467 not yet reported which blocks → SOUTHWESTERN BELL 9533 ARLINGTON TX
— 817-468 not yet reported which blocks → SOUTHWESTERN BELL 9533 ARLINGTON TX
— 817-469 not yet reported which blocks → SOUTHWESTERN BELL 9533 ARLINGTON TX
— 817-472 not yet reported which blocks → SOUTHWESTERN BELL 9533 ARLINGTON TX
— 817-473 not yet reported which blocks → SOUTHWESTERN BELL 9533 MANSFIELD TX
— 817-474 0XXX which blocks → SOUTHWESTERN BELL 9533 ROANOKE TX
— 817-475 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 GLENDALE TX
— 817-476 0–9 XXXall 10 · 6 holders which blocks → PAETEC ITEL, LLC 829J KENNEDALE TX
— 817-477 6XXX7XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 MANSFIELD TX
— 817-478 not yet reported which blocks → SOUTHWESTERN BELL 9533 KENNEDALE TX
— 817-479 3XXX4XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → ONVOY, LLC - TX 903C NRICHLDHLS TX
— 817-480 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 GLENDALE TX
— 817-481 not yet reported which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 GRAPEVINE TX
— 817-482 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 KELLER TX
— 817-483 not yet reported which blocks → SOUTHWESTERN BELL 9533 KENNEDALE TX
— 817-484 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → PATHWAY COM-TEL, INC. - TX 8253 FORT WORTH TX
— 817-485 not yet reported which blocks → SOUTHWESTERN BELL 9533 NRICHLDHLS TX
— 817-486 not yet reported which blocks → GRANDE COMMUNICATIONS NETWORKS, INC. - TX 7670 GRAPEVINE TX
— 817-488 not yet reported which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 GRAPEVINE TX
— 817-489 0XXX3XXX4XXX5XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-490 not yet reported which blocks → SOUTHWESTERN BELL 9533 ROANOKE TX
— 817-491 not yet reported which blocks → SOUTHWESTERN BELL 9533 ROANOKE TX
— 817-492 1XXX5XXX6XXX which blocks → SOUTHWESTERN BELL 9533 GLENDALE TX
— 817-493 not yet reported which blocks → SOUTHWESTERN BELL 9533 ARLINGTON TX
— 817-494 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 EULESS TX
— 817-495 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-496 not yet reported which blocks → SOUTHWESTERN BELL 9533 GLENDALE TX
— 817-497 8XXX which blocks → GRANDE COMMUNICATIONS NETWORKS, INC. - TX 7670 ROANOKE TX
— 817-498 not yet reported which blocks → SOUTHWESTERN BELL 9533 NRICHLDHLS TX
— 817-499 not yet reported which blocks → SPOK, INC. 6630 ARLINGTON TX
— 817-500 1XXX2XXX3XXX4XXX6XXX7XXX8XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - TX 6114 NRICHLDHLS TX
— 817-501 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-502 0–9 XXXall 10 · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - TX 6114 FORT WORTH TX
— 817-504 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ARLINGTON TX
— 817-505 3XXX5XXX6XXX7XXX8XXX9XXX which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - TX 7148 ARLINGTON TX
— 817-506 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - TX 6114 CLEBURNE TX
— 817-507 3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → ONVOY, LLC - TX 903C GLENDALE TX
— 817-508 1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - TX 7148 EULESS TX

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.