NumberResearch Membership · Data 09/20/2026

Thousands-blocks in 231-887

This prefix’s ten 1,000-number blocks and who holds each — 10 on record · from the daily NANPA thousands-block report, 09/20/2026

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

The ten 1,000-number thousand-blocks inside prefix 231-887 and who was initially assigned each. Under pooling these blocks often belong to different carriers — the single prefix-level “assignee” is usually just the pool / code holder, not who holds the numbers. ← all 231 blocks

Most active assignees, all time — NPA 231
NEW CINGULAR WIRELESS PCS, LLC - IL 3
OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2
TELEPORT COMMUNICATIONS AMERICA, LLC - MI 1
KALEVA TELEPHONE COMPANY - MI 1
CYNERGYCOMM.NET, INC. - MI 1
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 thousands-block assignments
AssignedThousands-blockLast 4 digitsStatusAssigneeOCNRate centerState
— 231-887-0XXX 0000–0999Reserved NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MANISTEE MI
2007-09-18 231-887-1XXX 1000–1999Assigned OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 MANISTEE MI
2005-01-12 231-887-2XXX 2000–2999Assigned ACD TELECOM, INC. - MI 3535 MANISTEE MI
2005-07-29 231-887-3XXX 3000–3999Assigned CYNERGYCOMM.NET, INC. - MI 9245 MANISTEE MI
2007-01-17 231-887-4XXX 4000–4999Assigned CHARTER IP ENABLED SERVICES, LLC 792K MANISTEE MI
2011-12-08 231-887-5XXX 5000–5999Assigned TELEPORT COMMUNICATIONS AMERICA, LLC - MI 770E MANISTEE MI
2008-05-30 231-887-6XXX 6000–6999Assigned KALEVA TELEPHONE COMPANY - MI 392F MANISTEE MI
2006-12-15 231-887-7XXX 7000–7999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MANISTEE MI
2025-08-28 231-887-8XXX 8000–8999Assigned OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 MANISTEE MI
2006-12-15 231-887-9XXX 9000–9999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MANISTEE MI

Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.