NumberResearch Membership · Data 09/20/2026

Recent thousands-block assignments

11 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, last 30 days — NPA 331
ONVOY, LLC 6
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 3
NEW CINGULAR WIRELESS PCS, LLC - IL 1
BANDWIDTH.COM CLEC, LLC - IL 1
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
2012-01-18 331-202-8XXX 8000–8999Assigned T-MOBILE USA, INC. 6529 ELMHURST IL
2012-01-13 331-999-2XXX 2000–2999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 OSWEGO IL
2012-01-09 331-201-0XXX 0000–0999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 DOWNERSGRV IL
2012-01-09 331-201-1XXX 1000–1999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 DOWNERSGRV IL
2011-12-07 331-588-8XXX 8000–8999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ST CHARLES IL
2011-12-01 331-200-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - IL 6115 BARTLETT IL
2011-11-10 331-213-1XXX 1000–1999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NAPERVILLE IL
2011-11-07 331-207-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - IL 6115 YORKVILLE IL
2011-10-28 331-444-6XXX 6000–6999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 NAPERVILLE IL
2011-10-24 331-205-0XXX 0000–0999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-10-24 331-205-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-10-14 331-203-0XXX 0000–0999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-10-14 331-203-1XXX 1000–1999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-10-14 331-203-2XXX 2000–2999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-10-14 331-203-3XXX 3000–3999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-10-14 331-203-4XXX 4000–4999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-10-14 331-203-5XXX 5000–5999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-10-14 331-203-6XXX 6000–6999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-10-14 331-203-7XXX 7000–7999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-10-14 331-203-8XXX 8000–8999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-10-14 331-206-0XXX 0000–0999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-10-11 331-999-4XXX 4000–4999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 OSWEGO IL
2011-10-10 331-223-0XXX 0000–0999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ST CHARLES IL
2011-10-10 331-332-0XXX 0000–0999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NAPERVILLE IL
2011-10-03 331-223-9XXX 9000–9999Assigned PEERLESS NETWORK OF ILLINOIS, LLC - IL 063E ST CHARLES IL
2011-09-21 331-588-4XXX 4000–4999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ST CHARLES IL
2011-09-14 331-256-0XXX 0000–0999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 AURORA IL
2011-09-09 331-220-4XXX 4000–4999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 AURORA IL
2011-09-09 331-220-5XXX 5000–5999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 AURORA IL
2011-09-07 331-213-0XXX 0000–0999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 NAPERVILLE IL
2011-08-23 331-225-5XXX 5000–5999Assigned T-MOBILE USA, INC. 6529 ELMHURST IL
2011-08-22 331-223-3XXX 3000–3999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 ST CHARLES IL
2011-08-10 331-588-5XXX 5000–5999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ST CHARLES IL
2011-08-08 331-223-2XXX 2000–2999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 ST CHARLES IL
2011-08-02 331-999-1XXX 1000–1999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E OSWEGO IL
2011-07-27 331-431-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-07-12 331-200-0XXX 0000–0999Assigned T-MOBILE USA, INC. 6529 BARTLETT IL
2011-07-12 331-200-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 BARTLETT IL
2011-07-12 331-220-0XXX 0000–0999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-07-12 331-220-1XXX 1000–1999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-07-12 331-220-2XXX 2000–2999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-07-12 331-220-3XXX 3000–3999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-07-12 331-220-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-06-29 331-588-3XXX 3000–3999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ST CHARLES IL
2011-06-16 331-431-1XXX 1000–1999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2011-06-07 331-222-9XXX 9000–9999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E ST CHARLES IL
2011-06-07 331-248-3XXX 3000–3999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E GENEVA IL
2011-05-19 331-444-5XXX 5000–5999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E NAPERVILLE IL
2011-05-19 331-999-0XXX 0000–0999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E OSWEGO IL
2011-05-12 331-444-3XXX 3000–3999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NAPERVILLE IL

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.