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
Clear Download CSV ↓
Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
— 817-870 6XXX which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-871 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-872 not yet reported which blocks → LEVEL 3 OF TELECOM OF TEXAS, LLC - TX 7516 FORT WORTH TX
— 817-873 0–9 XXXall 10 · 7 holders which blocks → PEERLESS NETWORK OF TEXAS, LLC - TX 177F GRAPEVINE TX
— 817-874 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-875 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-877 6XXX7XXX which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-878 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-880 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - TX 7148 GLENDALE TX
— 817-881 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-882 6XXX which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-884 6XXX7XXX which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-885 0XXX4XXX5XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-886 none assigned yet which blocks → LEVEL 3 COMMUNICATIONS, LLC - TX 6114 FORT WORTH TX
— 817-887 6XXX7XXX8XXX9XXX · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 FORT WORTH TX
— 817-890 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 ROANOKE TX
— 817-891 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-892 not yet reported which blocks → SOUTHWESTERN BELL 9533 ARLINGTON TX
— 817-893 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - TX 7148 NRICHLDHLS TX
— 817-895 not yet reported which blocks → MATRIX TELECOM, LLC. S/I/I TNCI - TX 7715 WEATHERFD TX
— 817-896 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-898 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - TX 6114 KELLER TX
— 817-900 0XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - TX 6114 FORT WORTH TX
— 817-903 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-904 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - TX 903C ACTON TX
— 817-905 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - TX 6506 ARLINGTON TX
— 817-906 not yet reported which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 GRAPEVINE TX
— 817-907 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ARLINGTON TX
— 817-909 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - TX 6506 ARLINGTON TX
— 817-910 3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → TEXAS WINDSTREAM, LLC 2153 ACTON TX
— 817-911 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX TX
— 817-912 1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL TELEPHONE COMPANY - TX 7726 GRAPEVINE TX
— 817-913 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - TX 6506 ARLINGTON TX
— 817-914 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX which blocks → GRANDE COMMUNICATIONS NETWORKS, INC. - TX 7670 ARLINGTON TX
— 817-915 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - TX 6506 ARLINGTON TX
— 817-916 0XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 FORT WORTH TX
— 817-917 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ARLINGTON TX
— 817-918 0–9 XXXall 10 · 6 holders which blocks → METROPCS, INC. 5562 NRICHLDHLS TX
— 817-919 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-920 2XXX3XXX4XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-921 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-922 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-923 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-924 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-925 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 GLENDALE TX
— 817-926 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-927 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-928 0XXX1XXX2XXX6XXX7XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - TX 6114 FORT WORTH TX
— 817-929 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 GLENDALE TX
— 817-930 not yet reported which blocks → SOUTHWESTERN BELL 9533 GLENDALE 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.