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 231
NEW CINGULAR WIRELESS PCS, LLC - IL 72
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
2026-03-19 231-469 0XXX1XXX4XXX9XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MUSKEGON MI
2025-05-22 231-341 0XXX9XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LAKE ANN MI
2024-09-05 231-456 0XXX9XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 GLEN LAKE MI
2022-08-12 231-410 0XXX1XXX2XXX4XXX7XXX8XXX9XXX · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MANISTEE MI
2021-10-06 231-387 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 PETOSKEY MI
2020-11-03 231-281 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CADILLAC MI
2017-08-09 231-939 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 PETOSKEY MI
2016-07-29 231-495 0XXX1XXX3XXX4XXX5XXX7XXX8XXX9XXX · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 BELLAIRE MI
2014-09-26 231-434 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MANTON MI
2009-07-17 231-245 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NEWAYGO MI
2005-09-13 231-288 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MUSKEGON MI
2005-04-11 231-833 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 WOLVERINE MI
2005-01-19 231-450 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 HESPERIA MI
2004-10-05 231-404 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 STANWOOD MI
2004-03-19 231-203 2XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ALANSON MI
2004-03-05 231-201 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CHIPPEWALK MI
2004-03-05 231-202 0XXX2XXX3XXX4XXX5XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MECOSTA MI
2002-12-30 231-360 2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 TRAVERSECY MI
2002-09-03 231-907 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LUDINGTON MI
2002-08-30 231-432 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NORTHPORT MI
2002-08-30 231-640 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LAKE ANN MI
2002-08-30 231-651 1XXX2XXX3XXX5XXX7XXX8XXX9XXX · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 BEULAH MI
2002-08-30 231-667 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MARION MI
2002-08-30 231-676 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 BELLAIRE MI
2002-08-30 231-729 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 IRONS MI
2002-08-30 231-794 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MANISTEE MI
2002-08-30 231-835 1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 GLEN LAKE MI
2002-08-30 231-866 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 SUTTONSBAY MI
2002-08-30 231-912 1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 REED CITY MI
2002-08-30 231-970 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 BEAR LAKE MI
2002-03-29 231-570 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 FIFE LAKE MI
2002-03-29 231-675 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 BOYNE CITY MI
2002-03-29 231-838 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 PETOSKEY MI
— 231-282 6XXX7XXX9XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 GRANT MI
— 231-290 2XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 INDIAN RIV MI
— 231-307 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MORLEY MI
— 231-313 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 TRAVERSECY MI
— 231-327 4XXX8XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MUSKEGON MI
— 231-329 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MUSKEGON MI
— 231-335 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 FREMONT MI
— 231-337 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MCBAIN 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
— 231-414 1XXX2XXX3XXX4XXX7XXX8XXX9XXX · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NEWAYGO MI
— 231-465 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 REED CITY MI
— 231-497 0–9 XXXall 10 · 7 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 BOYNE CITY MI
— 231-510 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MANISTEE MI
— 231-563 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MUSKEGON MI
— 231-564 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 KALKASKA MI
— 231-598 4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 BIG RAPIDS MI

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.