NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

0 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, all time — NPA 231
NEW CINGULAR WIRELESS PCS, LLC - IL 72
MICHIGAN BELL TEL CO 72
FRONTIER NORTH, INC. - MI 52
ONVOY, LLCV - MI 49
TELNET WORLDWIDE, INC. 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
— 231-347 not yet reported which blocks → MICHIGAN BELL TEL CO 9323 PETOSKEY MI
— 231-348 not yet reported which blocks → MICHIGAN BELL TEL CO 9323 PETOSKEY MI
— 231-349 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 BIG RAPIDS MI
— 231-351 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J SCOTTVILLE MI
— 231-352 0XXX1XXX3XXX · 3 holders which blocks → MICHIGAN BELL TEL CO 9323 FRANKFORT MI
— 231-353 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J MCBAIN MI
— 231-354 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 6 holders which blocks → MICHIGAN BELL TEL CO 9323 CORAL MI
— 231-355 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J FREMONT MI
— 231-356 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J MANCELONA MI
— 231-357 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 TRAVERSECY MI
— 231-358 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J CENTRAL LK MI
— 231-361 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J MORLEY MI
— 231-362 not yet reported which blocks → KALEVA TEL. CO. 0703 KALEVA MI
— 231-363 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J CHEBOYGAN MI
— 231-365 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J WOLVERINE MI
— 231-368 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J BALDWIN MI
— 231-369 not yet reported which blocks → ACE TEL. CO. OF MICHIGAN, INC. 0704 SOBOARDMAN MI
— 231-372 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J EVART MI
— 231-375 0–9 XXXall 10 · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MUSKEGON MI
— 231-377 0XXX1XXX2XXX3XXX5XXX8XXX · 5 holders which blocks → FRONTIER NORTH, INC. - MI 0695 CLAM RIVER MI
— 231-378 not yet reported which blocks → ACE TEL. CO. OF MICHIGAN, INC. 0704 COPESHTNVL MI
— 231-386 0XXX1XXX2XXX3XXX4XXX6XXX8XXX · 6 holders which blocks → MICHIGAN BELL TEL CO 9323 NORTHPORT MI
— 231-389 1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → MICHIGAN BELL TEL CO 9323 HARRIETTA MI
— 231-395 not yet reported which blocks → TELNET WORLDWIDE, INC. 817J GRANT MI
— 231-398 5XXX7XXX8XXX · 2 holders which blocks → MICHIGAN BELL TEL CO 9323 MANISTEE MI
— 231-408 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 BIG RAPIDS MI
— 231-409 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 TRAVERSECY MI
— 231-411 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MI
— 231-414 1XXX2XXX3XXX4XXX7XXX8XXX9XXX · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NEWAYGO MI
— 231-416 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 BIG RAPIDS MI
— 231-420 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 CHEBOYGAN MI
— 231-423 not yet reported which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E EVART MI
— 231-425 1XXX2XXX3XXX4XXX5XXX9XXX · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 LUDINGTON MI
— 231-436 0XXX1XXX2XXX3XXX6XXX · 5 holders which blocks → MICHIGAN BELL TEL CO 9323 MACKINAWCY MI
— 231-437 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 CHARLEVOIX MI
— 231-439 not yet reported which blocks → MICHIGAN BELL TEL CO 9323 PETOSKEY MI
— 231-448 6XXX7XXX8XXX9XXX · 2 holders which blocks → ISLAND TEL. CO. 0677 ST JAMES MI
— 231-452 0XXX3XXX6XXX9XXX · 4 holders which blocks → COMCAST IP PHONE, LLC 318J NEWAYGO MI
— 231-457 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → ACD TELECOM, INC. - MI 3535 MUSKEGON MI
— 231-460 2XXX3XXX6XXX9XXX · 2 holders which blocks → ONVOY, LLCV - MI 543C BIG RAPIDS MI
— 231-462 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → MICHIGAN BELL TEL CO 9323 FOUNTAIN MI
— 231-463 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 TRAVERSECY MI
— 231-464 0XXX1XXX2XXX3XXX6XXX7XXX · 6 holders which blocks → MICHIGAN BELL TEL CO 9323 FREESOIL MI
— 231-465 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 REED CITY MI
— 231-475 0XXX1XXX2XXX7XXX8XXX9XXX · 6 holders which blocks → BANDWIDTH.COM CLEC, LLC - MI 991E MANTON MI
— 231-477 not yet reported which blocks → KALEVA TEL. CO. 0703 BRETHREN MI
— 231-486 1XXX5XXX6XXX7XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI 7157 TRAVERSECY MI
— 231-487 2XXX6XXX8XXX · 3 holders which blocks → MICHIGAN BELL TEL CO 9323 PETOSKEY MI
— 231-492 0XXX3XXX5XXX6XXX7XXX · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 TRAVERSECY MI
— 231-494 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 BIG RAPIDS 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.