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
— 281-309 1XXX2XXX4XXX6XXX7XXX8XXX · 2 holders which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 DICKINSON TX
— 281-310 0XXX1XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → AT&T - LOCAL 7421 HSTNSUBURB TX
— 281-311 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX TX
— 281-312 9XXX which blocks → BRIGHTSPEED OF TEXAS, INC. 2114 HUMBLE TX
— 281-313 not yet reported which blocks → WINDSTREAM SUGAR LAND, LLC 2147 SUGAR LAND TX
— 281-314 not yet reported which blocks → WINDSTREAM SUGAR LAND, LLC 2147 SUGAR LAND TX
— 281-315 0XXX3XXX4XXX5XXX6XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 BAMMEL TX
— 281-316 not yet reported which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 LEAGUECITY TX
— 281-317 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - TX 903C FRIENDSWD TX
— 281-318 1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → GRANDE COMMUNICATIONS NETWORKS, INC. - TX 7670 HUMBLE TX
— 281-319 not yet reported which blocks → BRIGHTSPEED OF TEXAS, INC. 2114 HUMBLE TX
— 281-320 4XXX which blocks → SOUTHWESTERN BELL 9533 TOMBALL TX
— 281-321 not yet reported which blocks → WINDSTREAM SUGAR LAND, LLC 2147 SUGAR LAND TX
— 281-322 not yet reported which blocks → WINDSTREAM SUGAR LAND, LLC 2147 SUGAR LAND TX
— 281-323 0XXX1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 SPRING TX
— 281-324 0XXX8XXX · 2 holders which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 HUFFMAN TX
— 281-325 not yet reported which blocks → WINDSTREAM SUGAR LAND, LLC 2147 SUGAR LAND TX
— 281-326 6XXX9XXX which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 KEMAH TX
— 281-327 not yet reported which blocks → WINDSTREAM SUGAR LAND, LLC 2147 SUGAR LAND TX
— 281-328 not yet reported which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 CROSBY TX
— 281-329 not yet reported which blocks → WINDSTREAM SUGAR LAND, LLC 2147 SUGAR LAND TX
— 281-331 not yet reported which blocks → SOUTHWESTERN BELL 9533 ALVIN TX
— 281-332 not yet reported which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 LEAGUECITY TX
— 281-333 not yet reported which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 2154 KEMAH TX
— 281-334 not yet reported which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 KEMAH TX
— 281-335 6XXX which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 2154 KEMAH TX
— 281-336 0XXX1XXX8XXX9XXX · 2 holders which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 2154 KEMAH TX
— 281-337 not yet reported which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 DICKINSON TX
— 281-338 not yet reported which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 LEAGUECITY TX
— 281-339 4XXX7XXX8XXX9XXX · 2 holders which blocks → FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 4344 KEMAH TX
— 281-340 not yet reported which blocks → WINDSTREAM SUGAR LAND, LLC 2147 SUGAR LAND TX
— 281-341 not yet reported which blocks → SOUTHWESTERN BELL 9533 RICHMNRNBG TX
— 281-342 not yet reported which blocks → SOUTHWESTERN BELL 9533 RICHMNRNBG TX
— 281-343 3XXX4XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 SMITHERSLK TX
— 281-344 2XXX which blocks → SOUTHWESTERN BELL 9533 RICHMNRNBG TX
— 281-345 not yet reported which blocks → SOUTHWESTERN BELL 9533 LANGHAMCRK TX
— 281-346 3XXX4XXX5XXX7XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 VLY LODGE TX
— 281-347 not yet reported which blocks → CONSOLIDATED COMMUNICATIONS OF TEXAS COMPANY 2072 KATY TX
— 281-348 5XXX6XXX which blocks → BRIGHTSPEED OF TEXAS, INC. 2114 HUMBLE TX
— 281-349 not yet reported which blocks → SPOK, INC. 6630 HSTNSUBURB TX
— 281-350 not yet reported which blocks → SOUTHWESTERN BELL 9533 SPRING TX
— 281-351 not yet reported which blocks → SOUTHWESTERN BELL 9533 TOMBALL TX
— 281-352 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 HOUSTON TX
— 281-353 not yet reported which blocks → SOUTHWESTERN BELL 9533 SPRING TX
— 281-354 not yet reported which blocks → BRIGHTSPEED OF TEXAS, INC. 2114 PORTER TX
— 281-355 not yet reported which blocks → SOUTHWESTERN BELL 9533 SPRING TX
— 281-356 0XXX which blocks → SOUTHWESTERN BELL 9533 PINEHURST TX
— 281-357 9XXX which blocks → SOUTHWESTERN BELL 9533 TOMBALL TX
— 281-358 not yet reported which blocks → BRIGHTSPEED OF TEXAS, INC. 2114 HUMBLE TX
— 281-359 not yet reported which blocks → BRIGHTSPEED OF TEXAS, INC. 2114 HUMBLE 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.