NumberResearch Membership · Data 09/20/2026

Thousands-blocks in 443-678

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 443-678 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
CORE COMMUNICATIONS, INC.- MD 3
ONVOY, LLC - MD 2
OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 2
VERIZON MARYLAND, INC. 1
NEW CINGULAR WIRELESS PCS, LLC - DC 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
2014-08-06 443-678-0XXX 0000–0999Assigned ONVOY, LLC - MD 876D PARKVILLE MD
— 443-678-1XXX 1000–1999Reserved VERIZON MARYLAND, INC. 9212 PARKVILLE MD
2016-01-06 443-678-2XXX 2000–2999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 PARKVILLE MD
2018-05-11 443-678-3XXX 3000–3999Assigned NEW CINGULAR WIRELESS PCS, LLC - DC 4036 PARKVILLE MD
2019-04-15 443-678-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PARKVILLE MD
2024-01-25 443-678-5XXX 5000–5999Assigned ONVOY, LLC - MD 876D PARKVILLE MD
2018-05-23 443-678-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PARKVILLE MD
2018-05-23 443-678-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PARKVILLE MD
2015-10-28 443-678-8XXX 8000–8999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 PARKVILLE MD
2015-10-28 443-678-9XXX 9000–9999Assigned OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 PARKVILLE 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.