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
2018-10-18 443-782-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 ANNAPOLIS MD
2018-10-17 443-734-6XXX 6000–6999Assigned NEW CINGULAR WIRELESS PCS, LLC - DC 4036 SEVERN MD
2018-10-17 443-879-4XXX 4000–4999Assigned NEW CINGULAR WIRELESS PCS, LLC - DC 4036 DUNDALK MD
2018-10-11 443-264-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
2018-10-11 443-284-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 WATERLO238 MD
2018-10-11 443-346-5XXX 5000–5999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SEVERNA PK MD
2018-10-11 443-346-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SEVERNA PK MD
2018-10-11 443-346-8XXX 8000–8999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SEVERNA PK MD
2018-10-11 443-346-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SEVERNA PK MD
2018-10-11 443-363-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SEVERN MD
2018-10-11 443-675-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 RANDALLSTN MD
2018-10-11 443-688-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SEVERN MD
2018-10-11 443-796-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
2018-10-11 443-898-0XXX 0000–0999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
2018-10-11 443-946-3XXX 3000–3999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PARKVILLE MD
2018-10-11 443-946-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PARKVILLE MD
2018-10-11 443-946-5XXX 5000–5999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PARKVILLE MD
2018-10-11 443-946-8XXX 8000–8999Assigned CORE COMMUNICATIONS, INC.- MD 2593 PARKVILLE MD
2018-10-10 443-258-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EASTON MD
2018-10-10 443-258-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EASTON MD
2018-10-10 443-298-3XXX 3000–3999Assigned CORE COMMUNICATIONS, INC.- MD 2593 EASTON MD
2018-10-10 443-533-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 JARRETTSVL MD
2018-10-10 443-533-8XXX 8000–8999Assigned CORE COMMUNICATIONS, INC.- MD 2593 JARRETTSVL MD
2018-10-10 443-586-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 DUNDALK MD
2018-10-10 443-586-3XXX 3000–3999Assigned CORE COMMUNICATIONS, INC.- MD 2593 DUNDALK MD
2018-10-10 443-586-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 DUNDALK MD
2018-10-10 443-644-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 JARRETTSVL MD
2018-10-10 443-644-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 JARRETTSVL MD
2018-10-10 443-644-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 JARRETTSVL MD
2018-10-10 443-696-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 DUNDALK MD
2018-10-09 443-728-3XXX 3000–3999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BERLIN MD
2018-10-09 443-728-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BERLIN MD
2018-10-09 443-728-5XXX 5000–5999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BERLIN MD
2018-10-09 443-728-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BERLIN MD
2018-10-09 443-728-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BERLIN MD
2018-10-09 443-728-8XXX 8000–8999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BERLIN MD
2018-10-09 443-836-8XXX 8000–8999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2018-10-09 443-836-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2018-09-25 443-877-3XXX 3000–3999Assigned METROPCS, INC. 5562 NORTH EAST MD
2018-09-25 443-922-3XXX 3000–3999Assigned METROPCS, INC. 5562 EDGEWOOD MD
2018-09-24 443-936-6XXX 6000–6999Assigned CENTURYLINK COMMUNICATIONS, LLC 508J ELKRIDGE MD
2018-09-21 443-788-1XXX 1000–1999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F ABERDEEN MD
2018-09-20 443-431-8XXX 8000–8999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F RANDALLSTN MD
2018-09-20 443-512-7XXX 7000–7999Assigned METROPCS, INC. 5562 EDGEWOOD MD
2018-09-20 443-589-5XXX 5000–5999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F COCKEYSVL MD
2018-09-20 443-978-2XXX 2000–2999Assigned METROPCS, INC. 5562 SALISBURY MD
2018-09-19 443-505-6XXX 6000–6999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F ESSEX MD
2018-09-14 443-269-1XXX 1000–1999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 TOWSON MD
2018-09-14 443-269-9XXX 9000–9999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 TOWSON MD
2018-09-14 443-652-8XXX 8000–8999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 TOWSON 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.