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 512
SOUTHWESTERN BELL 274
NEW CINGULAR WIRELESS PCS, LLC - IL 98
T-MOBILE USA, INC. 70
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - TX 49
LEVEL 3 OF TELECOM OF TEXAS, LLC - TX 45
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
— 512-472 not yet reported which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-473 9XXX which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-474 not yet reported which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-475 none assigned yet which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-476 not yet reported which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-477 not yet reported which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-478 not yet reported which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-479 not yet reported which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-480 not yet reported which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-481 2XXX7XXX8XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-482 not yet reported which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-483 1XXX4XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-484 4XXX5XXX6XXX7XXX8XXX9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AUSTIN TX
— 512-485 not yet reported which blocks → LEVEL 3 OF TELECOM OF TEXAS, LLC - TX 7516 AUSTIN TX
— 512-486 0XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-487 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-488 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 2154 FENTRESS TX
— 512-489 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 2154 BRIGGS TX
— 512-490 not yet reported which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-491 not yet reported which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-492 2XXX3XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-493 not yet reported which blocks → LEVEL 3 OF TELECOM OF TEXAS, LLC - TX 7516 AUSTIN TX
— 512-494 4XXX5XXX6XXX which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-495 not yet reported which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-496 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AUSTIN TX
— 512-497 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AUSTIN TX
— 512-498 not yet reported which blocks → LEVEL 3 OF TELECOM OF TEXAS, LLC - TX 7516 AUSTIN TX
— 512-499 2XXX which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-502 2XXX4XXX5XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-504 3XXX6XXX7XXX9XXX · 3 holders which blocks → GRANDE COMMUNICATIONS NETWORKS, INC. - TX 7670 KYLE TX
— 512-505 8XXX which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-506 0XXX1XXX which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-507 none assigned yet which blocks → T-MOBILE USA, INC. 6529 AUSTIN TX
— 512-508 7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 GEORGETOWN TX
— 512-509 0–9 XXXwhole prefix which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - TX 7138 GEORGETOWN TX
— 512-510 not yet reported which blocks → SOUTHWESTERN BELL 9533 XXXXXXXXXX TX
— 512-511 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX TX
— 512-514 0XXX1XXX3XXX4XXX5XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-515 1XXX2XXX3XXX4XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 LIBERTY HL TX
— 512-517 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AUSTIN TX
— 512-518 0–9 XXXall 10 · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - TX 004F AUSTIN TX
— 512-519 1XXX2XXX4XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 OF TELECOM OF TEXAS, LLC - TX 7516 AUSTIN TX
— 512-520 0–9 XXXall 10 · 5 holders which blocks → TWC IP ENABLED SERVICES, LLC 793K AUSTIN TX
— 512-521 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 BASTROP TX
— 512-523 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → GRANDE COMMUNICATIONS NETWORKS, INC. - TX 7670 BUDA TX
— 512-524 3XXX6XXX7XXX9XXX which blocks → GRANDE COMMUNICATIONS NETWORKS, INC. - TX 7670 AUSTIN TX
— 512-525 2XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 LAMPASAS TX
— 512-527 3XXX4XXX6XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 AUSTIN TX
— 512-528 3XXX4XXX5XXX6XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 LEANDER TX
— 512-530 not yet reported which blocks → LEVEL 3 OF TELECOM OF TEXAS, LLC - TX 7516 AUSTIN 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.