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
2016-04-01 331-307-4XXX 4000–4999Assigned ONVOY, LLC 224C LOMBARD IL
2016-04-01 331-307-5XXX 5000–5999Assigned ONVOY, LLC 224C LOMBARD IL
2016-04-01 331-704-2XXX 2000–2999Assigned ONVOY, LLC 224C KANEVILLE IL
2016-04-01 331-704-3XXX 3000–3999Assigned ONVOY, LLC 224C KANEVILLE IL
2016-04-01 331-716-4XXX 4000–4999Assigned ONVOY, LLC 224C WHEATON IL
2016-04-01 331-716-5XXX 5000–5999Assigned ONVOY, LLC 224C WHEATON IL
2016-04-01 331-716-6XXX 6000–6999Assigned ONVOY, LLC 224C WHEATON IL
2016-04-01 331-888-7XXX 7000–7999Assigned ONVOY, LLC 224C WARRENVL IL
2016-04-01 331-888-8XXX 8000–8999Assigned ONVOY, LLC 224C WARRENVL IL
2016-03-24 331-310-2XXX 2000–2999Assigned ONVOY, LLC 224C BIG ROCK IL
2016-03-24 331-310-3XXX 3000–3999Assigned ONVOY, LLC 224C BIG ROCK IL
2016-03-21 331-204-2XXX 2000–2999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NAPERVILLE IL
2016-03-21 331-253-4XXX 4000–4999Assigned ONVOY, LLC 224C LEMONT IL
2016-03-21 331-253-5XXX 5000–5999Assigned ONVOY, LLC 224C LEMONT IL
2016-03-21 331-276-1XXX 1000–1999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ST CHARLES IL
2016-03-21 331-771-9XXX 9000–9999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ST CHARLES IL
2016-03-21 331-775-9XXX 9000–9999Assigned MCIMETRO ACCESS TRANSMISSION SERVICES LLC - IL 7196 DOWNERSGRV IL
2016-03-21 331-979-7XXX 7000–7999Assigned COMCAST IP PHONE, LLC 318J ELMHURST IL
2016-03-18 331-300-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2016-03-15 331-263-0XXX 0000–0999Assigned ONVOY, LLC 224C ITASCA IL
2016-03-15 331-263-1XXX 1000–1999Assigned ONVOY, LLC 224C ITASCA IL
2016-03-14 331-321-1XXX 1000–1999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 AURORA IL
2016-03-14 331-321-3XXX 3000–3999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2016-03-14 331-321-6XXX 6000–6999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2016-03-10 331-808-1XXX 1000–1999Assigned ONVOY, LLC 224C PLANO IL
2016-03-10 331-808-2XXX 2000–2999Assigned ONVOY, LLC 224C PLANO IL
2016-02-22 331-254-5XXX 5000–5999Assigned TELEPORT COMMUNICATIONS AMERICA, LLC - IL 7136 SUGARGROVE IL
2016-02-18 331-871-7XXX 7000–7999Assigned ONVOY, LLC 224C W CHICAGO IL
2016-02-18 331-871-8XXX 8000–8999Assigned ONVOY, LLC 224C W CHICAGO IL
2016-02-17 331-307-3XXX 3000–3999Assigned ONVOY, LLC 224C LOMBARD IL
2016-02-16 331-308-9XXX 9000–9999Assigned ONVOY, LLC 224C BARTLETT IL
2016-02-16 331-310-7XXX 7000–7999Assigned ONVOY, LLC 224C BIG ROCK IL
2016-02-16 331-310-8XXX 8000–8999Assigned ONVOY, LLC 224C BIG ROCK IL
2016-02-16 331-888-5XXX 5000–5999Assigned ONVOY, LLC 224C WARRENVL IL
2016-02-16 331-888-6XXX 6000–6999Assigned ONVOY, LLC 224C WARRENVL IL
2016-02-15 331-771-7XXX 7000–7999Assigned ONVOY, LLC 224C ST CHARLES IL
2016-02-15 331-771-8XXX 8000–8999Assigned ONVOY, LLC 224C ST CHARLES IL
2016-02-12 331-704-1XXX 1000–1999Assigned ONVOY, LLC 224C KANEVILLE IL
2016-02-10 331-806-2XXX 2000–2999Assigned ONVOY, LLC 224C WHEATON IL
2016-02-10 331-806-5XXX 5000–5999Assigned ONVOY, LLC 224C WHEATON IL
2016-02-08 331-304-0XXX 0000–0999Assigned ONVOY, LLC 224C BARTLETT IL
2016-02-08 331-304-1XXX 1000–1999Assigned ONVOY, LLC 224C BARTLETT IL
2016-02-04 331-254-3XXX 3000–3999Assigned ONVOY, LLC 224C SUGARGROVE IL
2016-02-04 331-254-4XXX 4000–4999Assigned ONVOY, LLC 224C SUGARGROVE IL
2016-02-04 331-717-0XXX 0000–0999Assigned ONVOY, LLC 224C OSWEGO IL
2016-02-04 331-717-1XXX 1000–1999Assigned ONVOY, LLC 224C OSWEGO IL
2016-01-28 331-308-7XXX 7000–7999Assigned ONVOY, LLC 224C BARTLETT IL
2016-01-28 331-308-8XXX 8000–8999Assigned ONVOY, LLC 224C BARTLETT IL
2016-01-28 331-901-4XXX 4000–4999Assigned ONVOY, LLC 224C ST CHARLES IL
2016-01-28 331-901-6XXX 6000–6999Assigned ONVOY, LLC 224C ST CHARLES 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.