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 281
SOUTHWESTERN BELL 283
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - TX 66
FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 57
NEW CINGULAR WIRELESS PCS, LLC - IL 50
WINDSTREAM SUGAR LAND, LLC 38
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
— 281-465 2XXX6XXX which blocks → SOUTHWESTERN BELL 9533 SPRING TX
— 281-466 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 SPRING TX
— 281-468 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 HOUSTON TX
— 281-469 not yet reported which blocks → SOUTHWESTERN BELL 9533 SATSUMA TX
— 281-470 not yet reported which blocks → SOUTHWESTERN BELL 9533 LA PORTE TX
— 281-471 not yet reported which blocks → SOUTHWESTERN BELL 9533 LA PORTE TX
— 281-472 not yet reported which blocks → SPOK, INC. 6630 HOUSTON TX
— 281-474 not yet reported which blocks → SOUTHWESTERN BELL 9533 SEABROOK TX
— 281-476 6XXX7XXX which blocks → SOUTHWESTERN BELL 9533 DEER PARK TX
— 281-477 not yet reported which blocks → SOUTHWESTERN BELL 9533 SATSUMA TX
— 281-478 9XXX which blocks → SOUTHWESTERN BELL 9533 DEER PARK TX
— 281-479 not yet reported which blocks → SOUTHWESTERN BELL 9533 DEER PARK TX
— 281-480 not yet reported which blocks → SOUTHWESTERN BELL 9533 APOLLO TX
— 281-481 not yet reported which blocks → SOUTHWESTERN BELL 9533 HSTNSUBURB TX
— 281-482 not yet reported which blocks → SOUTHWESTERN BELL 9533 FRIENDSWD TX
— 281-483 not yet reported which blocks → SOUTHWESTERN BELL 9533 APOLLO TX
— 281-484 not yet reported which blocks → SOUTHWESTERN BELL 9533 HSTNSUBURB TX
— 281-485 not yet reported which blocks → SOUTHWESTERN BELL 9533 HSTNSUBURB TX
— 281-486 not yet reported which blocks → SOUTHWESTERN BELL 9533 APOLLO TX
— 281-487 not yet reported which blocks → SOUTHWESTERN BELL 9533 HSTNSUBURB TX
— 281-488 not yet reported which blocks → SOUTHWESTERN BELL 9533 APOLLO TX
— 281-489 not yet reported which blocks → SOUTHWESTERN BELL 9533 MANVEL TX
— 281-490 not yet reported which blocks → WINDSTREAM SUGAR LAND, LLC 2147 SUGAR LAND TX
— 281-491 not yet reported which blocks → WINDSTREAM SUGAR LAND, LLC 2147 SUGAR LAND TX
— 281-492 4XXX which blocks → SOUTHWESTERN BELL 9533 BARKER TX
— 281-493 not yet reported which blocks → SOUTHWESTERN BELL 9533 HSTNSUBURB TX
— 281-494 not yet reported which blocks → WINDSTREAM SUGAR LAND, LLC 2147 SUGAR LAND TX
— 281-495 not yet reported which blocks → SOUTHWESTERN BELL 9533 HSTNSUBURB TX
— 281-496 not yet reported which blocks → SOUTHWESTERN BELL 9533 HSTNSUBURB TX
— 281-497 9XXX which blocks → SOUTHWESTERN BELL 9533 HSTNSUBURB TX
— 281-498 9XXX which blocks → SOUTHWESTERN BELL 9533 HSTNSUBURB TX
— 281-499 not yet reported which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 STAFFORD TX
— 281-500 0XXX1XXX3XXX5XXX7XXX8XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - TX 6114 LANGHAMCRK TX
— 281-502 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX 7239 HIGHLANDS TX
— 281-503 1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → GRANDE COMMUNICATIONS NETWORKS, INC. - TX 7670 PORTER HTS TX
— 281-504 5XXX7XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - TX 7239 HSTNSUBURB TX
— 281-506 0XXX2XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - TX 7138 HSTNSUBURB TX
— 281-507 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - TX 6506 HOUSTON TX
— 281-509 0XXX1XXX2XXX3XXX4XXX5XXX7XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 HSTNSUBURB TX
— 281-510 not yet reported which blocks → SPOK, INC. 6630 HOUSTON TX
— 281-511 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX TX
— 281-513 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 HOUSTON TX
— 281-514 not yet reported which blocks → SOUTHWESTERN BELL 9533 BAMMEL TX
— 281-516 5XXX6XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 TOMBALL TX
— 281-517 not yet reported which blocks → SOUTHWESTERN BELL 9533 SATSUMA TX
— 281-518 not yet reported which blocks → SOUTHWESTERN BELL 9533 BAMMEL TX
— 281-519 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - TX 6114 MANVEL TX
— 281-521 not yet reported which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 KEMAH TX
— 281-522 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 KEMAH TX
— 281-523 not yet reported which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 KEMAH 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.