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 623
LEVEL 3 COMMUNICATIONS, LLC - AZ 97
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
2022-12-01 623-290-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2022-04-19 623-283-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2022-03-29 623-284-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2021-10-07 623-274-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2021-10-07 623-274-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2021-07-21 623-273-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2021-06-29 623-270-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2021-06-10 623-270-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2021-05-19 623-270-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2021-05-19 623-270-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2020-12-30 623-269-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2020-12-30 623-269-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2020-09-16 623-265-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2020-09-16 623-265-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2020-03-31 623-254-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2020-03-31 623-254-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2020-01-08 623-253-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2019-08-07 623-259-1XXX 1000–1999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2019-06-18 623-259-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2019-02-12 623-246-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2018-07-24 623-439-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2018-03-30 623-231-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2018-03-30 623-231-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2018-03-27 623-289-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2018-03-27 623-289-9XXX 9000–9999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2015-08-19 623-522-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2015-08-19 623-522-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2015-03-23 623-900-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2015-03-23 623-900-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2015-03-23 623-900-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2015-03-23 623-900-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2015-03-23 623-900-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2015-03-23 623-900-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2013-03-11 623-777-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2013-03-11 623-777-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2013-03-11 623-777-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2010-02-11 623-209-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2010-02-11 623-209-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2009-11-05 623-258-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2009-11-05 623-432-0XXX 0000–0999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2009-11-05 623-432-1XXX 1000–1999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2009-08-26 623-223-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2009-08-26 623-223-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2009-05-20 623-738-0XXX 0000–0999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2009-05-20 623-738-1XXX 1000–1999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2009-05-20 623-738-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2009-05-20 623-738-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2009-04-16 623-806-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2008-10-16 623-201-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2008-10-16 623-201-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ

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.