NumberResearch Membership · Data 09/19/2026

Recent thousands-block assignments

11 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, 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
2009-01-23 331-481-1XXX 1000–1999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 DOWNERSGRV IL
2009-01-22 331-221-0XXX 0000–0999Assigned ILLINOIS BELL TEL CO 9329 ELMHURST IL
2009-01-22 331-221-1XXX 1000–1999Assigned ILLINOIS BELL TEL CO 9329 ELMHURST IL
2009-01-22 331-221-2XXX 2000–2999Assigned ILLINOIS BELL TEL CO 9329 ELMHURST IL
2009-01-22 331-221-3XXX 3000–3999Assigned ILLINOIS BELL TEL CO 9329 ELMHURST IL
2009-01-22 331-221-4XXX 4000–4999Assigned ILLINOIS BELL TEL CO 9329 ELMHURST IL
2009-01-22 331-221-5XXX 5000–5999Assigned ILLINOIS BELL TEL CO 9329 ELMHURST IL
2009-01-22 331-221-6XXX 6000–6999Assigned ILLINOIS BELL TEL CO 9329 ELMHURST IL
2009-01-22 331-221-7XXX 7000–7999Assigned ILLINOIS BELL TEL CO 9329 ELMHURST IL
2009-01-22 331-221-8XXX 8000–8999Assigned ILLINOIS BELL TEL CO 9329 ELMHURST IL
2009-01-22 331-221-9XXX 9000–9999Assigned ILLINOIS BELL TEL CO 9329 ELMHURST IL
2009-01-21 331-442-4XXX 4000–4999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E ST CHARLES IL
2009-01-21 331-472-7XXX 7000–7999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E NAPERVILLE IL
2009-01-21 331-481-9XXX 9000–9999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E DOWNERSGRV IL
2008-12-30 331-472-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - IL 6115 NAPERVILLE IL
2008-12-02 331-465-7XXX 7000–7999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 W CHICAGO IL
2008-11-25 331-472-1XXX 1000–1999Assigned ONVOY, LLC 224C NAPERVILLE IL
2008-11-25 331-826-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 ELMHURST IL
2008-11-17 331-422-0XXX 0000–0999Assigned LEVEL 3 COMMUNICATIONS, LLC - IL 6115 ST CHARLES IL
2008-11-17 331-457-0XXX 0000–0999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 NAPERVILLE IL
2008-11-17 331-457-7XXX 7000–7999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 NAPERVILLE IL
2008-11-17 331-457-9XXX 9000–9999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 NAPERVILLE IL
2008-11-13 331-465-9XXX 9000–9999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E W CHICAGO IL
2008-11-13 331-642-0XXX 0000–0999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E ELMHURST IL
2008-11-13 331-684-7XXX 7000–7999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E AURORA IL
2008-11-13 331-684-8XXX 8000–8999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E AURORA IL
2008-11-10 331-465-3XXX 3000–3999Assigned PAETEC ITEL, LLC 829J W CHICAGO IL
2008-11-07 331-551-0XXX 0000–0999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LOMBARD IL
2008-11-07 331-551-1XXX 1000–1999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LOMBARD IL
2008-11-07 331-551-2XXX 2000–2999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LOMBARD IL
2008-11-04 331-333-0XXX 0000–0999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NAPERVILLE IL
2008-10-31 331-222-0XXX 0000–0999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ST CHARLES IL
2008-10-31 331-222-1XXX 1000–1999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ST CHARLES IL
2008-10-30 331-442-7XXX 7000–7999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 ST CHARLES IL
2008-10-30 331-442-9XXX 9000–9999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 ST CHARLES IL
2008-10-30 331-481-0XXX 0000–0999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 DOWNERSGRV IL
2008-10-24 331-643-4XXX 4000–4999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC - IL 7196 AURORA IL
2008-10-23 331-472-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 NAPERVILLE IL
2008-10-06 331-452-4XXX 4000–4999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AURORA IL
2008-10-06 331-575-0XXX 0000–0999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AURORA IL
2008-10-06 331-575-1XXX 1000–1999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AURORA IL
2008-10-06 331-575-2XXX 2000–2999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AURORA IL
2008-10-06 331-575-3XXX 3000–3999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AURORA IL
2008-10-06 331-575-4XXX 4000–4999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AURORA IL
2008-10-06 331-575-5XXX 5000–5999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AURORA IL
2008-10-06 331-575-6XXX 6000–6999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AURORA IL
2008-08-26 331-462-1XXX 1000–1999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC - IL 7196 LOMBARD IL
2008-08-22 331-330-0XXX 0000–0999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NAPERVILLE IL
2008-08-22 331-330-1XXX 1000–1999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NAPERVILLE IL
2008-07-31 331-262-8XXX 8000–8999Assigned T-MOBILE USA, INC. 6529 AURORA IL

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.