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
— 231-613 1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 SCOTTVILLE MI
— 231-614 not yet reported which blocks → 123.NET, LLC 2550 PENTWATER MI
— 231-615 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 CHEBOYGAN MI
— 231-616 not yet reported which blocks → MI
— 231-620 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 TRAVERSECY MI
— 231-624 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 KALKASKA MI
— 231-625 3XXX4XXX5XXX6XXX7XXX · 4 holders which blocks → MICHIGAN BELL TEL CO 9323 CHEBOYGAN MI
— 231-627 0XXX which blocks → MICHIGAN BELL TEL CO 9323 CHEBOYGAN MI
— 231-629 3XXX4XXX5XXX8XXX9XXX · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 BIG RAPIDS MI
— 231-632 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 TRAVERSECY MI
— 231-633 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 TRAVERSECY MI
— 231-634 1XXX2XXX6XXX8XXX · 2 holders which blocks → ISLAND TEL. CO. 0677 BOIS BLANC MI
— 231-645 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 TRAVERSECY MI
— 231-648 2XXX3XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MI 6120 HOWARDCITY MI
— 231-652 0XXX which blocks → MICHIGAN BELL TEL CO 9323 NEWAYGO MI
— 231-689 4XXX8XXX9XXX · 3 holders which blocks → MICHIGAN BELL TEL CO 9323 WHITECLOUD MI
— 231-700 not yet reported which blocks → MI
— 231-709 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 TRAVERSECY MI
— 231-711 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MI
— 231-712 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 MUSKEGON MI
— 231-714 0XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 TRAVERSECY MI
— 231-715 1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 7 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 TRAVERSECY MI
— 231-719 5XXX6XXX7XXX · 2 holders which blocks → FRONTIER NORTH, INC. - MI 0695 MUSKEGON MI
— 231-720 0XXX4XXX5XXX6XXX8XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - MI 0695 MUSKEGON MI
— 231-722 not yet reported which blocks → FRONTIER NORTH, INC. - MI 0695 MUSKEGON MI
— 231-723 not yet reported which blocks → MICHIGAN BELL TEL CO 9323 MANISTEE MI
— 231-724 0XXX which blocks → FRONTIER NORTH, INC. - MI 0695 MUSKEGON MI
— 231-725 5XXX which blocks → FRONTIER NORTH, INC. - MI 0695 MUSKEGON MI
— 231-726 0XXX7XXX8XXX · 3 holders which blocks → FRONTIER NORTH, INC. - MI 0695 MUSKEGON MI
— 231-727 not yet reported which blocks → FRONTIER NORTH, INC. - MI 0695 MUSKEGON MI
— 231-728 not yet reported which blocks → FRONTIER NORTH, INC. - MI 0695 MUSKEGON MI
— 231-730 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MUSKEGON MI
— 231-731 not yet reported which blocks → 123.NET, LLC 2550 SHELBY MI
— 231-732 3XXX6XXX · 2 holders which blocks → ONVOY SPECTRUM, LLC 624H MORLEY MI
— 231-733 not yet reported which blocks → FRONTIER NORTH, INC. - MI 0695 MUSKEGON MI
— 231-734 1XXX8XXX · 2 holders which blocks → MICHIGAN BELL TEL CO 9323 EVART MI
— 231-736 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → FRONTIER NORTH, INC. - MI 0695 MUSKEGON MI
— 231-737 not yet reported which blocks → FRONTIER NORTH, INC. - MI 0695 MUSKEGON MI
— 231-739 not yet reported which blocks → FRONTIER NORTH, INC. - MI 0695 MUSKEGON MI
— 231-740 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 MUSKEGON MI
— 231-742 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 HART MI
— 231-743 0XXX1XXX3XXX4XXX5XXX7XXX8XXX · 5 holders which blocks → MICHIGAN BELL TEL CO 9323 MARION MI
— 231-744 not yet reported which blocks → FRONTIER NORTH, INC. - MI 0695 MUSKEGON MI
— 231-745 5XXX which blocks → MICHIGAN BELL TEL CO 9323 BALDWIN MI
— 231-747 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → FRONTIER NORTH, INC. - MI 0695 MUSKEGON MI
— 231-750 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MUSKEGON MI
— 231-755 not yet reported which blocks → FRONTIER NORTH, INC. - MI 0695 MUSKEGON MI
— 231-757 7XXX which blocks → MICHIGAN BELL TEL CO 9323 SCOTTVILLE MI
— 231-758 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 PETOSKEY MI
— 231-759 not yet reported which blocks → FRONTIER NORTH, INC. - MI 0695 MUSKEGON 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.