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
TC SYSTEMS, INC. 20
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
Clear Download CSV ↓
Recent thousands-block assignments
AssignedThousands-blockLast 4 digitsStatusAssigneeOCNRate centerState
2024-02-27 857-231-4XXX 4000–4999Assigned TC SYSTEMS, INC. 7135 NEWTON MA
2023-05-17 857-354-4XXX 4000–4999Assigned TC SYSTEMS, INC. 7135 BOSTON MA
2021-01-28 857-367-7XXX 7000–7999Assigned TC SYSTEMS, INC. 7135 WATERTOWN MA
2020-10-05 857-367-6XXX 6000–6999Assigned TC SYSTEMS, INC. 7135 WATERTOWN MA
2020-04-06 857-524-6XXX 6000–6999Assigned TC SYSTEMS, INC. 7135 SO BOSTON MA
2018-01-26 857-338-8XXX 8000–8999Assigned TC SYSTEMS, INC. 7135 BOSTON MA
2018-01-26 857-338-9XXX 9000–9999Assigned TC SYSTEMS, INC. 7135 BOSTON MA
2016-10-10 857-760-3XXX 3000–3999Assigned TC SYSTEMS, INC. 7135 WATERTOWN MA
2016-08-16 857-760-2XXX 2000–2999Assigned TC SYSTEMS, INC. 7135 WATERTOWN MA
2016-05-20 857-971-2XXX 2000–2999Assigned TC SYSTEMS, INC. 7135 CHARLESTN MA
2015-05-22 857-304-6XXX 6000–6999Assigned TC SYSTEMS, INC. 7135 WATERTOWN MA
2015-03-24 857-304-8XXX 8000–8999Assigned TC SYSTEMS, INC. 7135 WATERTOWN MA
2014-09-30 857-304-5XXX 5000–5999Assigned TC SYSTEMS, INC. 7135 WATERTOWN MA
2013-03-14 857-304-3XXX 3000–3999Assigned TC SYSTEMS, INC. 7135 WATERTOWN MA
2012-10-18 857-816-6XXX 6000–6999Assigned TC SYSTEMS, INC. 7135 WINTHROP MA
2012-10-17 857-342-6XXX 6000–6999Assigned TC SYSTEMS, INC. 7135 HYDE PARK MA
2009-07-14 857-574-3XXX 3000–3999Assigned TC SYSTEMS, INC. 7135 EASTBOSTON MA
2005-11-14 857-383-4XXX 4000–4999Assigned TC SYSTEMS, INC. 7135 BOSTON MA
2005-11-14 857-383-5XXX 5000–5999Assigned TC SYSTEMS, INC. 7135 BOSTON MA
2005-08-16 857-221-4XXX 4000–4999Assigned TC SYSTEMS, INC. 7135 BOSTON 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.