NumberResearch Membership · Data 09/20/2026

Thousands-blocks in 575-233

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 575-233 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 575 blocks

Most active assignees, all time — NPA 575
QWEST CORPORATION 7
LEVEL 3 COMMUNICATIONS, LLC - NM 2
ONVOY, LLC - NM 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
— 575-233-0XXX 0000–0999Reserved QWEST CORPORATION 9636 LA MESA NM
— 575-233-1XXX 1000–1999Reserved QWEST CORPORATION 9636 LA MESA NM
— 575-233-2XXX 2000–2999Reserved QWEST CORPORATION 9636 LA MESA NM
— 575-233-3XXX 3000–3999Reserved QWEST CORPORATION 9636 LA MESA NM
— 575-233-4XXX 4000–4999Reserved QWEST CORPORATION 9636 LA MESA NM
— 575-233-5XXX 5000–5999Reserved QWEST CORPORATION 9636 LA MESA NM
2006-10-02 575-233-6XXX 6000–6999Assigned ONVOY, LLC - NM 206F LA MESA NM
2004-10-18 575-233-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - NM 5470 LA MESA NM
2008-09-05 575-233-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - NM 5470 LA MESA NM
— 575-233-9XXX 9000–9999Reserved QWEST CORPORATION 9636 LA MESA NM

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.