NumberResearch Membership · Data 09/24/2026

Recent thousands-block assignments

0 blocks assigned in the last 30 days · from the daily NANPA thousands-block report, 09/24/2026

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
MCIMETRO ACCESS TRANSMISSION SERVICES LLC 69
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
2019-07-09 623-259-3XXX 3000–3999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2018-09-21 623-244-2XXX 2000–2999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2017-02-15 623-233-8XXX 8000–8999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2015-09-30 623-745-3XXX 3000–3999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2015-06-17 623-499-3XXX 3000–3999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2015-02-17 623-759-7XXX 7000–7999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2014-09-03 623-850-5XXX 5000–5999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2013-07-22 623-666-7XXX 7000–7999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2013-07-15 623-312-1XXX 1000–1999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2013-07-15 623-777-5XXX 5000–5999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2013-04-18 623-383-2XXX 2000–2999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2012-06-01 623-299-4XXX 4000–4999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2012-05-04 623-299-3XXX 3000–3999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2011-10-05 623-282-3XXX 3000–3999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2011-09-29 623-295-3XXX 3000–3999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2011-05-18 623-277-1XXX 1000–1999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2011-05-18 623-277-2XXX 2000–2999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2011-05-18 623-277-3XXX 3000–3999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2010-09-02 623-696-3XXX 3000–3999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2010-09-02 623-696-4XXX 4000–4999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2010-06-22 623-336-6XXX 6000–6999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2010-01-27 623-432-3XXX 3000–3999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2009-06-17 623-240-1XXX 1000–1999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2009-06-17 623-240-2XXX 2000–2999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2009-06-17 623-240-3XXX 3000–3999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2009-06-17 623-240-4XXX 4000–4999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2009-06-17 623-240-5XXX 5000–5999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2009-06-17 623-240-6XXX 6000–6999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2009-06-17 623-240-7XXX 7000–7999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2008-07-11 623-201-1XXX 1000–1999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2008-07-11 623-201-2XXX 2000–2999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2008-07-10 623-207-4XXX 4000–4999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2008-07-10 623-207-5XXX 5000–5999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2008-04-21 623-255-3XXX 3000–3999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2007-05-07 623-236-1XXX 1000–1999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2007-05-07 623-236-2XXX 2000–2999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2007-05-07 623-241-5XXX 5000–5999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2007-05-07 623-241-6XXX 6000–6999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2007-05-07 623-241-7XXX 7000–7999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2007-05-07 623-241-9XXX 9000–9999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2006-08-01 623-670-5XXX 5000–5999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2006-08-01 623-687-9XXX 9000–9999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2006-08-01 623-691-8XXX 8000–8999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2006-08-01 623-734-9XXX 9000–9999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2006-08-01 623-748-2XXX 2000–2999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2005-11-14 623-433-0XXX 0000–0999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2005-11-14 623-433-1XXX 1000–1999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2005-11-14 623-433-2XXX 2000–2999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2005-11-14 623-433-3XXX 3000–3999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ
2005-11-14 623-433-4XXX 4000–4999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 PHOENIX AZ

Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/24/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.