Thousands-blocks in 231-800

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 231-800 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

ONVOY, LLCV - MI 2

ONVOY SPECTRUM, LLC 1

CHARTER IP ENABLED SERVICES, LLC 1

AT&T ENTERPRISES, LLC 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

Recent thousands-block assignments
Assigned	Thousands-block	Last 4 digits	Status	Assignee	OCN	Rate center	State
2017-10-02	231-800-0XXX	0000–0999	Assigned	ONVOY, LLCV - MI	543C	LUTHER	MI
—	231-800-1XXX	1000–1999	Available			LUTHER	MI
2021-05-20	231-800-2XXX	2000–2999	Assigned	ONVOY SPECTRUM, LLC	624H	LUTHER	MI
—	231-800-3XXX	3000–3999	Available			LUTHER	MI
—	231-800-4XXX	4000–4999	Available			LUTHER	MI
2023-06-23	231-800-5XXX	5000–5999	Assigned	CHARTER IP ENABLED SERVICES, LLC	792K	LUTHER	MI
—	231-800-6XXX	6000–6999	Available			LUTHER	MI
2023-08-25	231-800-7XXX	7000–7999	Assigned	AT&T ENTERPRISES, LLC	516C	LUTHER	MI
2017-10-02	231-800-8XXX	8000–8999	Assigned	ONVOY, LLCV - MI	543C	LUTHER	MI
—	231-800-9XXX	9000–9999	Available			LUTHER	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.