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
2011-04-12 331-588-1XXX 1000–1999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ST CHARLES IL
2011-04-08 331-431-0XXX 0000–0999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AURORA IL
2011-04-01 331-444-0XXX 0000–0999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E NAPERVILLE IL
2011-04-01 331-444-1XXX 1000–1999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E NAPERVILLE IL
2011-04-01 331-444-2XXX 2000–2999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E NAPERVILLE IL
2011-03-18 331-588-0XXX 0000–0999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ST CHARLES IL
2011-02-24 331-457-4XXX 4000–4999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC - IL 7196 NAPERVILLE IL
2011-02-17 331-551-9XXX 9000–9999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E LOMBARD IL
2011-01-21 331-725-4XXX 4000–4999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 OSWEGO IL
2011-01-14 331-222-8XXX 8000–8999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 ST CHARLES IL
2011-01-06 331-442-5XXX 5000–5999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ST CHARLES IL
2011-01-06 331-442-6XXX 6000–6999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ST CHARLES IL
2010-12-03 331-248-2XXX 2000–2999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E GENEVA IL
2010-11-24 331-472-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - IL 6115 NAPERVILLE IL
2010-11-16 331-472-6XXX 6000–6999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 NAPERVILLE IL
2010-11-10 331-472-4XXX 4000–4999Assigned COMCAST IP PHONE, LLC 318J NAPERVILLE IL
2010-11-01 331-472-0XXX 0000–0999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E NAPERVILLE IL
2010-11-01 331-642-8XXX 8000–8999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E ELMHURST IL
2010-10-27 331-472-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - IL 6115 NAPERVILLE IL
2010-10-06 331-333-9XXX 9000–9999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 NAPERVILLE IL
2010-10-01 331-465-5XXX 5000–5999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E W CHICAGO IL
2010-10-01 331-725-2XXX 2000–2999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E OSWEGO IL
2010-09-30 331-222-7XXX 7000–7999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E ST CHARLES IL
2010-09-30 331-333-8XXX 8000–8999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E NAPERVILLE IL
2010-09-30 331-551-8XXX 8000–8999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E LOMBARD IL
2010-09-27 331-431-8XXX 8000–8999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 AURORA IL
2010-09-24 331-481-6XXX 6000–6999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E DOWNERSGRV IL
2010-09-24 331-625-5XXX 5000–5999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 DOWNERSGRV IL
2010-09-20 331-442-2XXX 2000–2999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ST CHARLES IL
2010-09-16 331-625-3XXX 3000–3999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 DOWNERSGRV IL
2010-09-16 331-625-4XXX 4000–4999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 DOWNERSGRV IL
2010-09-10 331-725-1XXX 1000–1999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 OSWEGO IL
2010-09-03 331-330-9XXX 9000–9999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E NAPERVILLE IL
2010-08-25 331-826-4XXX 4000–4999Assigned T-MOBILE USA, INC. 6529 ELMHURST IL
2010-08-23 331-457-5XXX 5000–5999Assigned COMCAST IP PHONE, LLC 318J NAPERVILLE IL
2010-08-13 331-826-2XXX 2000–2999Assigned ONVOY, LLC 224C ELMHURST IL
2010-08-13 331-826-3XXX 3000–3999Assigned ONVOY, LLC 224C ELMHURST IL
2010-08-12 331-465-2XXX 2000–2999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E W CHICAGO IL
2010-08-12 331-725-0XXX 0000–0999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E OSWEGO IL
2010-08-10 331-625-6XXX 6000–6999Assigned ONVOY, LLC 224C DOWNERSGRV IL
2010-08-10 331-625-7XXX 7000–7999Assigned ONVOY, LLC 224C DOWNERSGRV IL
2010-08-10 331-625-8XXX 8000–8999Assigned ONVOY, LLC 224C DOWNERSGRV IL
2010-08-04 331-457-3XXX 3000–3999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NAPERVILLE IL
2010-08-03 331-223-1XXX 1000–1999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 ST CHARLES IL
2010-07-29 331-222-6XXX 6000–6999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ST CHARLES IL
2010-07-26 331-431-7XXX 7000–7999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 AURORA IL
2010-07-15 331-248-1XXX 1000–1999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E GENEVA IL
2010-07-15 331-642-7XXX 7000–7999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E ELMHURST IL
2010-07-15 331-725-6XXX 6000–6999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 OSWEGO IL
2010-07-02 331-642-2XXX 2000–2999Assigned T-MOBILE USA, INC. 6529 ELMHURST 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.