NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

355 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026

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, last 30 days
8X8, INC. 38
ONVOY, LLC - CA 31
NEW CINGULAR WIRELESS PCS, LLC - IL 28
NEW CINGULAR WIRELESS PCS, LLC - DC 26
ONVOY, LLC - NJ 18
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
— 734-307 0–9 XXXall 10 · 5 holders which blocks → ONVOY, LLCV - MI 543C TRENTON MI
— 734-308 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 WYANDOTTE MI
— 734-309 4XXX5XXX6XXX7XXX · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 WYANDOTTE MI
— 734-310 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J DUNDEE MI
— 734-311 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MI
— 734-313 not yet reported which blocks → MI
— 734-314 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J GREGORY MI
— 734-316 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → COMCAST IP PHONE, LLC 318J SALINE MI
— 734-317 1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 6 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MI 770E ERIE MI
— 734-319 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J ERIE MI
— 734-320 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 ANN ARBOR MI
— 734-321 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J MAYBEE MI
— 734-322 0XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MONROE MI
— 734-323 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 ANN ARBOR MI
— 734-324 1XXX which blocks → MICHIGAN BELL TEL CO 9323 WYANDOTTE MI
— 734-325 0XXX1XXX3XXX4XXX5XXX8XXX9XXX · 4 holders which blocks → COMCAST IP PHONE, LLC 318J BELLEVILLE MI
— 734-326 not yet reported which blocks → MICHIGAN BELL TEL CO 9323 WAYNE MI
— 734-327 not yet reported which blocks → MICHIGAN BELL TEL CO 9323 ANN ARBOR MI
— 734-328 1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 BELLEVILLE MI
— 734-329 1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI 7279 WAYNE MI
— 734-330 2XXX which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 ANN ARBOR MI
— 734-331 0XXX1XXX5XXX7XXX8XXX · 3 holders which blocks → COMCAST IP PHONE, LLC 318J WAYNE MI
— 734-332 2XXX which blocks → MICHIGAN BELL TEL CO 9323 ANN ARBOR MI
— 734-334 0XXX3XXX6XXX7XXX8XXX which blocks → MICHIGAN BELL TEL CO 9323 WAYNE MI
— 734-335 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MI 770E PLYMOUTH MI
— 734-336 1XXX2XXX3XXX7XXX8XXX · 2 holders which blocks → ONVOY, LLCV - MI 543C MANCHESTER MI
— 734-337 4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 YPSILANTI MI
— 734-338 0XXX1XXX3XXX4XXX5XXX7XXX8XXX · 5 holders which blocks → COMCAST IP PHONE, LLC 318J LIVONIA MI
— 734-339 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 WHITMORELK MI
— 734-340 0XXX1XXX7XXX8XXX9XXX · 5 holders which blocks → COMCAST IP PHONE, LLC 318J YPSILANTI MI
— 734-341 none assigned yet which blocks → METROPCS, INC. 5562 TRENTON MI
— 734-342 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J MONROE MI
— 734-344 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MONROE MI
— 734-345 1XXX2XXX3XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI 7279 BELLEVILLE MI
— 734-347 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 TEMPERANCE MI
— 734-348 2XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 FLAT ROCK MI
— 734-349 1XXX2XXX3XXX6XXX8XXX · 2 holders which blocks → PAETEC ITEL, LLC 829J MONROE MI
— 734-351 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 WAYNE MI
— 734-352 0XXX1XXX6XXX7XXX9XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI 7279 ANN ARBOR MI
— 734-353 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ANN ARBOR MI
— 734-354 not yet reported which blocks → MICHIGAN BELL TEL CO 9323 PLYMOUTH MI
— 734-355 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ANN ARBOR MI
— 734-357 1XXX3XXX4XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI 7279 PLYMOUTH MI
— 734-358 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ANN ARBOR MI
— 734-362 4XXX9XXX · 2 holders which blocks → MICHIGAN BELL TEL CO 9323 TRENTON MI
— 734-365 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MI 770E TRENTON MI
— 734-366 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 WAYNE MI
— 734-367 4XXX which blocks → MICHIGAN BELL TEL CO 9323 LIVONIA MI
— 734-368 9XXX which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 ANN ARBOR MI
— 734-369 0XXX1XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → COMCAST IP PHONE, LLC 318J ANN ARBOR MI

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.