NumberResearch Membership · Data 09/19/2026

Thousands-blocks in 231-285

This prefix’s ten 1,000-number blocks and who holds each — 10 on record · from the daily NANPA thousands-block report, 09/19/2026

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

The ten 1,000-number thousand-blocks inside prefix 231-285 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
4
OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 3
PEERLESS NETWORK OF MICHIGAN, LLC - MI 1
METROPCS, INC. 1
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - 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
2020-03-30 231-285-0XXX 0000–0999Assigned PEERLESS NETWORK OF MICHIGAN, LLC - MI 933G CADILLAC MI
2020-08-12 231-285-1XXX 1000–1999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 6003 CADILLAC MI
— 231-285-2XXX 2000–2999Available CADILLAC MI
— 231-285-3XXX 3000–3999Available CADILLAC MI
— 231-285-4XXX 4000–4999Available CADILLAC MI
— 231-285-5XXX 5000–5999Available CADILLAC MI
2021-09-09 231-285-6XXX 6000–6999Assigned METROPCS, INC. 5562 CADILLAC MI
2020-01-10 231-285-7XXX 7000–7999Assigned OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 CADILLAC MI
2020-01-10 231-285-8XXX 8000–8999Assigned OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 CADILLAC MI
2020-01-10 231-285-9XXX 9000–9999Assigned OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC 2964 CADILLAC MI

Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.