NumberResearch Membership · Data 09/20/2026

Recent thousands-block assignments

70 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 667
NEW CINGULAR WIRELESS PCS, LLC - DC 38
ONVOY, LLC - MD 18
BANDWIDTH.COM CLEC, LLC - MD 6
METROPCS, INC. 2
INTRADO COMMUNICATIONS, LLC 2
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
2019-04-16 667-336-3XXX 3000–3999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BEL AIR MD
2019-04-16 667-336-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BEL AIR MD
2019-04-16 667-336-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BEL AIR MD
2019-04-16 667-336-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BEL AIR MD
2019-04-16 667-344-1XXX 1000–1999Assigned CORE COMMUNICATIONS, INC.- MD 2593 CHASE MD
2019-04-16 667-344-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 CHASE MD
2019-04-16 667-344-3XXX 3000–3999Assigned CORE COMMUNICATIONS, INC.- MD 2593 CHASE MD
2019-04-16 667-344-5XXX 5000–5999Assigned CORE COMMUNICATIONS, INC.- MD 2593 CHASE MD
2019-04-16 667-344-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 CHASE MD
2019-04-16 667-666-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 WEST RIVER MD
2019-04-16 667-706-0XXX 0000–0999Assigned CORE COMMUNICATIONS, INC.- MD 2593 ELKTON MD
2019-04-11 667-686-9XXX 9000–9999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F ELLICOTTCY MD
2019-04-08 667-722-8XXX 8000–8999Assigned BANDWIDTH.COM CLEC, LLC - MD 071F GLENWOOD MD
2019-03-27 667-204-9XXX 9000–9999Assigned IP HORIZON LLC 515J ANNAPOLIS MD
2019-03-27 667-256-0XXX 0000–0999Assigned IP HORIZON LLC 515J ABERDEEN MD
2019-03-27 667-258-1XXX 1000–1999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-27 667-258-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-27 667-258-3XXX 3000–3999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-27 667-258-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-27 667-258-5XXX 5000–5999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-27 667-258-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-27 667-258-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-27 667-258-8XXX 8000–8999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-27 667-258-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-27 667-269-9XXX 9000–9999Assigned IP HORIZON LLC 515J ELKTON MD
2019-03-27 667-312-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-27 667-312-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-27 667-444-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-27 667-653-8XXX 8000–8999Assigned IP HORIZON LLC 515J BRYNPKLNCM MD
2019-03-27 667-677-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-27 667-677-3XXX 3000–3999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-27 667-677-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
2019-03-25 667-265-3XXX 3000–3999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 VIENNA MD
2019-03-15 667-226-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 STMICHAELS MD
2019-03-15 667-226-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 STMICHAELS MD
2019-03-15 667-244-5XXX 5000–5999Assigned CORE COMMUNICATIONS, INC.- MD 2593 STILL POND MD
2019-03-15 667-244-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 STILL POND MD
2019-03-15 667-244-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 STILL POND MD
2019-03-15 667-277-2XXX 2000–2999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SHERWD FOR MD
2019-03-15 667-277-5XXX 5000–5999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SHERWD FOR MD
2019-03-15 667-277-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SHERWD FOR MD
2019-03-15 667-277-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SHERWD FOR MD
2019-03-15 667-277-8XXX 8000–8999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SHERWD FOR MD
2019-03-15 667-277-9XXX 9000–9999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SHERWD FOR MD
2019-03-15 667-364-3XXX 3000–3999Assigned CORE COMMUNICATIONS, INC.- MD 2593 STEVENSVL MD
2019-03-15 667-364-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 STEVENSVL MD
2019-03-15 667-364-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 STEVENSVL MD
2019-03-15 667-473-6XXX 6000–6999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SOLOMONS MD
2019-03-15 667-473-7XXX 7000–7999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SOLOMONS MD
2019-03-15 667-727-4XXX 4000–4999Assigned CORE COMMUNICATIONS, INC.- MD 2593 SUDLERSVL 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.