NumberResearch Membership · Data 09/19/2026

Recent thousands-block assignments

0 blocks assigned in the last 30 days · from the daily NANPA thousands-block report, 09/19/2026

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, all time — NPA 720
LEVEL 3 TELECOM OF COLORADO, LLC - CO 65
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
2017-09-05 720-603-2XXX 2000–2999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2015-12-18 720-728-3XXX 3000–3999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2015-10-15 720-646-3XXX 3000–3999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2015-07-23 720-990-2XXX 2000–2999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2014-10-21 720-573-5XXX 5000–5999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2014-04-08 720-372-5XXX 5000–5999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2014-04-02 720-593-5XXX 5000–5999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2014-04-02 720-593-7XXX 7000–7999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2013-07-23 720-456-3XXX 3000–3999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2013-07-23 720-456-4XXX 4000–4999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2013-07-10 720-744-4XXX 4000–4999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2013-05-09 720-478-0XXX 0000–0999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2013-05-09 720-478-1XXX 1000–1999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2013-05-09 720-478-2XXX 2000–2999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2013-05-09 720-478-3XXX 3000–3999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2013-05-09 720-478-4XXX 4000–4999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2013-05-09 720-478-5XXX 5000–5999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2013-05-09 720-478-6XXX 6000–6999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2013-05-09 720-478-7XXX 7000–7999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2013-05-09 720-478-8XXX 8000–8999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2013-05-09 720-478-9XXX 9000–9999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2012-09-04 720-387-2XXX 2000–2999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2012-09-04 720-387-3XXX 3000–3999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2012-09-04 720-387-4XXX 4000–4999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2012-06-18 720-625-6XXX 6000–6999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2012-06-18 720-625-7XXX 7000–7999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2012-05-29 720-612-5XXX 5000–5999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2012-05-29 720-612-6XXX 6000–6999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2011-12-02 720-245-6XXX 6000–6999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2011-07-01 720-354-3XXX 3000–3999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2011-02-10 720-440-6XXX 6000–6999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-09-27 720-458-2XXX 2000–2999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-06-07 720-393-1XXX 1000–1999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-06-07 720-393-2XXX 2000–2999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-06-07 720-393-3XXX 3000–3999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-06-07 720-393-4XXX 4000–4999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-06-07 720-393-5XXX 5000–5999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-06-07 720-393-6XXX 6000–6999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-06-07 720-393-7XXX 7000–7999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-06-07 720-393-8XXX 8000–8999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-04-28 720-282-8XXX 8000–8999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-03-31 720-754-0XXX 0000–0999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-03-31 720-754-1XXX 1000–1999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-03-31 720-754-2XXX 2000–2999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-03-31 720-754-3XXX 3000–3999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-03-31 720-754-4XXX 4000–4999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-03-31 720-754-5XXX 5000–5999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-03-31 720-754-6XXX 6000–6999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-03-31 720-754-7XXX 7000–7999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO
2010-03-31 720-754-8XXX 8000–8999Assigned LEVEL 3 TELECOM OF COLORADO, LLC - CO 4574 DENVER CO

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.