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
OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 28
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
Clear Download CSV ↓
Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
2025-07-31 231-552 2XXX9XXX · 2 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 CHARLEVOIX MI
2022-02-14 231-413 0XXX1XXX8XXX9XXX · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 KALKASKA MI
2022-01-10 231-380 0XXX1XXX3XXX7XXX8XXX9XXX · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 NEWAYGO MI
2021-11-03 231-397 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 MANISTEE MI
2021-10-26 231-390 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 BIG RAPIDS MI
2021-09-03 231-370 0–9 XXXall 10 · 5 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 MUSKEGON MI
2021-03-01 231-284 0–9 XXXall 10 · 7 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 MANISTEE MI
2020-01-09 231-285 0XXX1XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 CADILLAC MI
2019-10-24 231-254 0XXX1XXX2XXX3XXX4XXX5XXX7XXX9XXX · 5 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 PETOSKEY MI
2018-11-08 231-253 0–9 XXXall 10 · 5 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 CADILLAC MI
2017-05-17 231-493 0–9 XXXall 10 · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 TRAVERSECY MI
2017-03-03 231-260 0–9 XXXall 10 · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 MUSKEGON MI
2001-05-18 231-923 0–9 XXXall 10 · 5 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 HART MI
2001-04-02 231-642 2XXX3XXX4XXX5XXX8XXX9XXX · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 TRAVERSECY MI
2001-03-09 231-638 4XXX5XXX8XXX9XXX · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 MUSKEGON MI
2001-02-05 231-468 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 CADILLAC MI
2001-02-05 231-580 0XXX4XXX5XXX7XXX8XXX · 3 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 BIG RAPIDS MI
2001-01-09 231-392 0XXX5XXX7XXX8XXX · 2 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 TRAVERSECY MI
— 231-206 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 MUSKEGON MI
— 231-218 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 TRAVERSECY MI
— 231-343 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 MUSKEGON MI
— 231-425 1XXX2XXX3XXX4XXX5XXX9XXX · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 LUDINGTON MI
— 231-437 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 CHARLEVOIX MI
— 231-578 none assigned yet which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 MUSKEGON MI
— 231-624 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 KALKASKA MI
— 231-629 3XXX4XXX5XXX8XXX9XXX · 4 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 BIG RAPIDS MI
— 231-758 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 PETOSKEY MI
— 231-846 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 CADILLAC 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.