NumberResearch Membership · Data 09/20/2026

Recent thousands-block assignments

0 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, all time — NPA 857
LEVEL 3 COMMUNICATIONS, LLC - MA 92
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
2020-01-14 857-285-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 CAMBRIDGE MA
2019-09-09 857-335-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2019-08-20 857-354-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2019-08-20 857-354-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2019-08-07 857-354-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-10-18 857-306-0XXX 0000–0999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-10-18 857-306-1XXX 1000–1999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-10-18 857-306-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-10-18 857-306-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-10-18 857-306-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-10-18 857-306-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-10-18 857-306-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-10-18 857-306-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-10-18 857-306-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-10-18 857-315-0XXX 0000–0999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-10-18 857-315-1XXX 1000–1999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-10-18 857-315-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-10-18 857-315-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-08-18 857-296-1XXX 1000–1999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-03-01 857-287-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-03-01 857-287-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-02-03 857-895-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2017-02-03 857-895-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2016-03-02 857-880-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2016-01-26 857-504-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2016-01-26 857-504-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2015-11-19 857-990-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2015-11-19 857-990-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2015-09-02 857-972-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2015-08-10 857-972-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2015-08-10 857-972-9XXX 9000–9999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2015-07-24 857-270-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 CAMBRIDGE MA
2015-07-24 857-270-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 CAMBRIDGE MA
2015-07-14 857-706-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 CAMBRIDGE MA
2015-06-18 857-270-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 CAMBRIDGE MA
2015-04-22 857-770-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2015-04-01 857-706-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 CAMBRIDGE MA
2015-02-24 857-327-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2014-07-15 857-702-0XXX 0000–0999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2014-06-11 857-930-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2014-04-29 857-305-0XXX 0000–0999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2014-04-15 857-305-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2014-04-15 857-305-9XXX 9000–9999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2014-01-14 857-263-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2013-07-19 857-305-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2013-01-03 857-313-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2012-07-10 857-777-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 CAMBRIDGE MA
2012-06-05 857-250-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 BOSTON MA
2012-02-29 857-598-9XXX 9000–9999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 MILTON MA
2011-08-03 857-598-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - MA 4018 MILTON MA

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.