NumberResearch Membership · Data 09/20/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026

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
— 817-687 6XXX7XXX8XXX9XXX · 2 holders which blocks → ONVOY, LLC - TX 903C GLENDALE TX
— 817-688 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 GLENDALE TX
— 817-689 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-690 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-691 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-692 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 GLENDALE TX
— 817-695 5XXX which blocks → SOUTHWESTERN BELL 9533 ARLINGTON TX
— 817-696 0XXX1XXX3XXX5XXX6XXX7XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-698 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-700 not yet reported which blocks → TX
— 817-701 4XXX5XXX6XXX8XXX9XXX · 2 holders which blocks → ONVOY, LLC - TX 903C ARLINGTON TX
— 817-703 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-704 5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - TX 6114 ARLINGTON TX
— 817-705 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-706 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-707 none assigned yet which blocks → METROPCS, INC. 5562 ARLINGTON TX
— 817-708 2XXX which blocks → LEVEL 3 OF TELECOM OF TEXAS, LLC - TX 7516 FORT WORTH TX
— 817-709 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 GLENDALE TX
— 817-711 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX TX
— 817-712 not yet reported which blocks → LEVEL 3 OF TELECOM OF TEXAS, LLC - TX 7516 NRICHLDHLS TX
— 817-713 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 GLENDALE TX
— 817-714 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-715 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-717 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - TX 6114 FORT WORTH TX
— 817-719 5XXX6XXX7XXX8XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - TX 6114 ARLINGTON TX
— 817-720 0XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 FORT WORTH TX
— 817-721 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-722 4XXX5XXX6XXX · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - TX 7148 GRAPEVINE TX
— 817-723 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-724 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 GRAPEVINE TX
— 817-725 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - TX 6114 RENO TX
— 817-726 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-728 9XXX which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J MANSFIELD TX
— 817-729 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-730 1XXX3XXX4XXX5XXX6XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-731 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-732 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-734 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → GRANDE COMMUNICATIONS NETWORKS, INC. - TX 7670 GLENDALE TX
— 817-735 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-736 2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - TX 6114 GRANBURY TX
— 817-737 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-738 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-740 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-741 not yet reported which blocks → MILLENNIUM TELCOM, LLC DBA ONESOURCE COMM. - TX 4009 KELLER TX
— 817-742 0XXX2XXX which blocks → BANDWIDTH.COM CLEC, LLC - TX 004F ROANOKE TX
— 817-743 0XXX1XXX2XXX3XXX5XXX6XXX9XXX which blocks → T-MOBILE USA, INC. 6529 NRICHLDHLS TX
— 817-744 0XXX7XXX8XXX9XXX · 3 holders which blocks → CHARTER IP ENABLED SERVICES, LLC 792K FORT WORTH TX
— 817-745 0XXX5XXX6XXX7XXX9XXX which blocks → ONVOY, LLC - TX 903C KELLER TX
— 817-746 none assigned yet which blocks → BANDWIDTH.COM CLEC, LLC - TX 004F ROANOKE TX
— 817-747 0XXX1XXX2XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → ONVOY SPECTRUM, LLC 624H NRICHLDHLS TX

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.