NumberResearch Membership · Data 09/20/2026

Thousands-blocks in 443-329

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 443-329 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 443 blocks

Most active assignees, last 30 days — NPA 443
LEVEL 3 COMMUNICATIONS, LLC - MD 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
— 443-329-0XXX 0000–0999Available WATERLO236 MD
2026-08-25 443-329-1XXX 1000–1999Assigned LEVEL 3 COMMUNICATIONS, LLC - MD 6119 WATERLO236 MD
2006-01-24 443-329-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - MD 6119 WATERLO236 MD
2009-01-05 443-329-3XXX 3000–3999Assigned YMAX COMMUNICATIONS CORP. - MD 281E WATERLO236 MD
— 443-329-4XXX 4000–4999Reserved LEVEL 3 COMMUNICATIONS, LLC - MD 6119 WATERLO236 MD
2020-05-26 443-329-5XXX 5000–5999Assigned ONVOY, LLC - MD 876D WATERLO236 MD
2019-04-12 443-329-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 WATERLO236 MD
2019-04-12 443-329-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 WATERLO236 MD
2017-04-17 443-329-8XXX 8000–8999Assigned TELNYX LLC 073H WATERLO236 MD
2020-05-26 443-329-9XXX 9000–9999Assigned ONVOY, LLC - MD 876D WATERLO236 MD

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.