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
— 817-807 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX which blocks → AT&T - LOCAL 7421 ARLINGTON TX
— 817-808 not yet reported which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-809 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → GRANDE COMMUNICATIONS NETWORKS, INC. - TX 7670 GRAPEVINE TX
— 817-810 6XXX8XXX which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-811 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX TX
— 817-812 0XXX1XXX4XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - TX 6114 NRICHLDHLS TX
— 817-816 not yet reported which blocks → SOUTHWESTERN BELL 9533 ARLINGTON TX
— 817-819 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-820 9XXX which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-821 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ARLINGTON TX
— 817-822 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-824 not yet reported which blocks → SPOK, INC. 6630 ARLINGTON TX
— 817-825 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-827 not yet reported which blocks → SPOK, INC. 6630 ARLINGTON TX
— 817-829 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-831 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-832 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ARLINGTON TX
— 817-833 not yet reported which blocks → TELETOUCH COMMUNICATIONS, INC. 6591 ARLINGTON TX
— 817-834 9XXX which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-835 1XXX3XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 EULESS TX
— 817-836 not yet reported which blocks → GRANDE COMMUNICATIONS NETWORKS, INC. - TX 7670 EULESS TX
— 817-837 0XXX5XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 ROANOKE TX
— 817-838 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-839 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 KENNEDALE TX
— 817-840 3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - TX 7148 FORT WORTH TX
— 817-841 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-842 7XXX which blocks → ONVOY, LLC - TX 903C MANSFIELD TX
— 817-843 not yet reported which blocks → TELETOUCH COMMUNICATIONS, INC. 6591 ARLINGTON TX
— 817-844 not yet reported which blocks → EXIANT COMMUNICATIONS LLC 114J FORT WORTH TX
— 817-845 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-846 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ARLINGTON TX
— 817-847 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-849 0XXX2XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 NRICHLDHLS TX
— 817-850 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-852 5XXX6XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-853 not yet reported which blocks → MATRIX TELECOM, LLC. S/I/I TNCI - TX 7715 MANSFIELD TX
— 817-854 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 ROANOKE TX
— 817-855 0XXX6XXX9XXX which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J ARLINGTON TX
— 817-856 0XXX2XXX7XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 ARLINGTON TX
— 817-857 0XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - TX 6114 EULESS TX
— 817-858 not yet reported which blocks → SOUTHWESTERN BELL 9533 EULESS TX
— 817-859 0XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - TX 7148 ROANOKE TX
— 817-860 8XXX which blocks → SOUTHWESTERN BELL 9533 ARLINGTON TX
— 817-861 not yet reported which blocks → SOUTHWESTERN BELL 9533 ARLINGTON TX
— 817-862 0XXX1XXX3XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-865 0XXX1XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - TX 6114 GRAPEVINE TX
— 817-866 1XXX6XXX7XXX8XXX · 3 holders which blocks → TEXAS WINDSTREAM, LLC 2153 GRANDVIEW TX
— 817-867 not yet reported which blocks → SOUTHWESTERN BELL 9533 FORT WORTH TX
— 817-868 not yet reported which blocks → SOUTHWESTERN BELL 9533 EULESS TX
— 817-869 not yet reported which blocks → LEVEL 3 OF TELECOM OF TEXAS, LLC - TX 7516 FORT WORTH 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.