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
2021-06-02 331-399-4XXX 4000–4999Assigned ONVOY SPECTRUM, LLC 624H DOWNERSGRV IL
2021-06-02 331-400-9XXX 9000–9999Assigned IP HORIZON LLC 515J OSWEGO IL
2021-06-02 331-465-8XXX 8000–8999Assigned IP HORIZON LLC 515J W CHICAGO IL
2021-06-02 331-500-5XXX 5000–5999Assigned ONVOY SPECTRUM, LLC 624H GENEVA IL
2021-06-02 331-900-6XXX 6000–6999Assigned ONVOY SPECTRUM, LLC 624H ELMHURST IL
2021-06-02 331-946-2XXX 2000–2999Assigned ONVOY SPECTRUM, LLC 624H GLEN ELLYN IL
2021-06-01 331-850-8XXX 8000–8999Assigned ONVOY SPECTRUM, LLC 624H BIG ROCK IL
2021-05-21 331-261-1XXX 1000–1999Assigned IP HORIZON LLC 515J LEMONT IL
2021-05-21 331-266-1XXX 1000–1999Assigned IP HORIZON LLC 515J ST CHARLES IL
2021-05-21 331-899-0XXX 0000–0999Assigned IP HORIZON LLC 515J LOMBARD IL
2021-05-21 331-900-2XXX 2000–2999Assigned IP HORIZON LLC 515J ELMHURST IL
2021-05-20 331-356-0XXX 0000–0999Assigned IP HORIZON LLC 515J BARTLETT IL
2021-05-19 331-269-0XXX 0000–0999Assigned IP HORIZON LLC 515J AURORA IL
2021-05-19 331-345-0XXX 0000–0999Assigned IP HORIZON LLC 515J NAPERVILLE IL
2021-05-19 331-399-0XXX 0000–0999Assigned IP HORIZON LLC 515J DOWNERSGRV IL
2021-05-14 331-269-4XXX 4000–4999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2021-05-14 331-269-5XXX 5000–5999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2021-05-14 331-269-6XXX 6000–6999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2021-05-14 331-269-7XXX 7000–7999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2021-05-14 331-269-8XXX 8000–8999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2021-05-14 331-269-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2021-05-13 331-666-3XXX 3000–3999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2021-05-13 331-666-4XXX 4000–4999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2021-04-24 331-232-3XXX 3000–3999Assigned ONVOY SPECTRUM, LLC 624H W CHICAGO IL
2021-04-24 331-232-4XXX 4000–4999Assigned ONVOY SPECTRUM, LLC 624H W CHICAGO IL
2021-04-20 331-267-0XXX 0000–0999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LOMBARD IL
2021-02-23 331-399-6XXX 6000–6999Assigned TELEPORT COMMUNICATIONS AMERICA, LLC - IL 7136 DOWNERSGRV IL
2021-02-22 331-600-9XXX 9000–9999Assigned PEERLESS NETWORK OF ILLINOIS, LLC - IL 063E WHEATON IL
2021-02-02 331-268-1XXX 1000–1999Assigned ONVOY, LLC 224C SUGARGROVE IL
2021-02-02 331-268-2XXX 2000–2999Assigned ONVOY, LLC 224C SUGARGROVE IL
2021-02-02 331-268-3XXX 3000–3999Assigned ONVOY, LLC 224C SUGARGROVE IL
2021-02-02 331-310-6XXX 6000–6999Assigned ONVOY, LLC 224C BIG ROCK IL
2021-02-02 331-808-6XXX 6000–6999Assigned ONVOY, LLC 224C PLANO IL
2021-01-30 331-299-2XXX 2000–2999Assigned ONVOY, LLC 224C HINSDALE IL
2021-01-30 331-299-3XXX 3000–3999Assigned ONVOY, LLC 224C HINSDALE IL
2021-01-30 331-299-4XXX 4000–4999Assigned ONVOY, LLC 224C HINSDALE IL
2021-01-30 331-299-5XXX 5000–5999Assigned ONVOY, LLC 224C HINSDALE IL
2021-01-30 331-299-6XXX 6000–6999Assigned ONVOY, LLC 224C HINSDALE IL
2021-01-30 331-500-1XXX 1000–1999Assigned TELNYX LLC 073H GENEVA IL
2021-01-30 331-600-8XXX 8000–8999Assigned TELNYX LLC 073H WHEATON IL
2021-01-30 331-899-2XXX 2000–2999Assigned ONVOY, LLC 224C LOMBARD IL
2021-01-30 331-899-3XXX 3000–3999Assigned ONVOY, LLC 224C LOMBARD IL
2021-01-30 331-899-4XXX 4000–4999Assigned ONVOY, LLC 224C LOMBARD IL
2021-01-30 331-899-5XXX 5000–5999Assigned ONVOY, LLC 224C LOMBARD IL
2021-01-30 331-899-6XXX 6000–6999Assigned ONVOY, LLC 224C LOMBARD IL
2021-01-30 331-899-7XXX 7000–7999Assigned ONVOY, LLC 224C LOMBARD IL
2021-01-30 331-899-8XXX 8000–8999Assigned ONVOY, LLC 224C LOMBARD IL
2021-01-26 331-388-8XXX 8000–8999Assigned FRACTEL, LLC 965H SUGARGROVE IL
2021-01-26 331-399-9XXX 9000–9999Assigned FRACTEL, LLC 965H DOWNERSGRV IL
2021-01-26 331-788-8XXX 8000–8999Assigned FRACTEL, LLC 965H GENEVA 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.