NumberResearch Membership · Data 09/20/2026

Recent thousands-block assignments

17 blocks assigned in the last 30 days · from the daily NANPA thousands-block report, 09/20/2026

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

Most carrier growth happens here, not at the prefix level: under number pooling, carriers receive individual 1,000-number blocks (e.g. 626-470-0XXX) within already-assigned prefixes. Assignments are initial assignments — the current serving carrier of individual numbers may differ due to portability.

Most active assignees, last 30 days — NPA 443
ONVOY, LLC - MD 8
NEW CINGULAR WIRELESS PCS, LLC - DC 4
VERSATEL LLC 1
OPENTACT INC. 1
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
2019-04-15 443-920-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SYKESVILLE MD
2019-04-15 443-920-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SYKESVILLE MD
2019-04-15 443-946-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PARKVILLE 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
2019-04-12 443-376-1XXX 1000–1999Assigned CORE COMMUNICATIONS, INC.- MD 2593 DUNDALK MD
2019-04-12 443-376-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 DUNDALK MD
2019-04-12 443-456-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EDGEWOOD MD
2019-04-12 443-498-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 CATONSVL MD
2019-04-12 443-498-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 CATONSVL MD
2019-04-12 443-512-3XXX 3000–3999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EDGEWOOD MD
2019-04-12 443-512-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EDGEWOOD MD
2019-04-12 443-559-3XXX 3000–3999Assigned CORE COMMUNICATIONS, INC.- MD 2593 ESSEX MD
2019-04-12 443-581-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 CHASE MD
2019-04-12 443-587-0XXX 0000–0999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EDGEWOOD MD
2019-04-12 443-587-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EDGEWOOD MD
2019-04-12 443-587-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EDGEWOOD MD
2019-04-12 443-596-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 ESSEX MD
2019-04-12 443-626-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 CHASE MD
2019-04-12 443-628-0XXX 0000–0999Assigned CORE COMMUNICATIONS, INC.- MD 2593 GLENBURNIE MD
2019-04-12 443-777-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 ESSEX MD
2019-04-12 443-781-0XXX 0000–0999Assigned CORE COMMUNICATIONS, INC.- MD 2593 ARGRGBSNIS MD
2019-04-12 443-815-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 ESSEX MD
2019-04-12 443-879-0XXX 0000–0999Assigned CORE COMMUNICATIONS, INC.- MD 2593 DUNDALK MD
2019-04-10 443-376-4XXX 4000–4999Assigned COMCAST IP PHONE, LLC 318J DUNDALK MD
2019-04-05 443-334-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
2019-04-05 443-357-0XXX 0000–0999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
2019-04-05 443-357-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
2019-04-05 443-357-3XXX 3000–3999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
2019-04-05 443-357-5XXX 5000–5999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
2019-04-05 443-357-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
2019-04-05 443-357-8XXX 8000–8999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
2019-04-05 443-357-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
2019-04-05 443-816-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SEVERNA PK MD
2019-04-05 443-816-5XXX 5000–5999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SEVERNA PK MD
2019-04-05 443-816-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SEVERNA PK MD
2019-04-05 443-816-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SEVERNA PK MD
2019-03-28 443-774-0XXX 0000–0999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F COLUMBIA MD
2019-03-28 443-774-1XXX 1000–1999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F COLUMBIA MD
2019-03-27 443-258-8XXX 8000–8999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EASTON MD
2019-03-27 443-362-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EASTON MD
2019-03-27 443-362-5XXX 5000–5999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EASTON MD
2019-03-27 443-362-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EASTON MD
2019-03-27 443-362-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EASTON MD
2019-03-27 443-496-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EASTON MD
2019-03-27 443-496-8XXX 8000–8999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EASTON MD
2019-03-27 443-496-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EASTON MD
2019-03-27 443-592-8XXX 8000–8999Assigned IP HORIZON LLC 515J ELKRIDGE MD
2019-03-27 443-746-5XXX 5000–5999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EASTON MD
2019-03-27 443-746-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EASTON 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.