NumberResearch Membership · Data 09/19/2026

Thousands-blocks in 443-290

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 443-290 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, all time — NPA 443
BANDWIDTH.COM CLEC, LLC - MD 4
ONVOY, LLC - MD 2
LEVEL 3 TELECOM OF MARYLAND, LLC - MD 1
IP HORIZON LLC 1
CORE COMMUNICATIONS, INC.- 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
2004-03-04 443-290-0XXX 0000–0999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PARKVILLE MD
2013-08-12 443-290-1XXX 1000–1999Assigned IP HORIZON LLC 515J PARKVILLE MD
— 443-290-2XXX 2000–2999Reserved LEVEL 3 TELECOM OF MARYLAND, LLC - MD 7591 PARKVILLE MD
2016-03-15 443-290-3XXX 3000–3999Assigned ONVOY, LLC - MD 876D PARKVILLE MD
2013-12-20 443-290-4XXX 4000–4999Assigned COMCAST IP PHONE, LLC 318J PARKVILLE MD
2012-09-11 443-290-5XXX 5000–5999Assigned ONVOY, LLC - MD 876D PARKVILLE MD
2014-03-03 443-290-6XXX 6000–6999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F PARKVILLE MD
2016-07-18 443-290-7XXX 7000–7999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F PARKVILLE MD
2014-03-03 443-290-8XXX 8000–8999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F PARKVILLE MD
2016-07-18 443-290-9XXX 9000–9999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F PARKVILLE MD

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.