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
2018-10-22 331-242-5XXX 5000–5999Assigned T-MOBILE USA, INC. 6529 LOMBARD IL
2018-10-22 331-242-6XXX 6000–6999Assigned T-MOBILE USA, INC. 6529 LOMBARD IL
2018-10-22 331-242-7XXX 7000–7999Assigned T-MOBILE USA, INC. 6529 LOMBARD IL
2018-10-22 331-242-8XXX 8000–8999Assigned T-MOBILE USA, INC. 6529 LOMBARD IL
2018-10-22 331-242-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 LOMBARD IL
2018-10-22 331-243-1XXX 1000–1999Assigned T-MOBILE USA, INC. 6529 LOMBARD IL
2018-10-22 331-243-2XXX 2000–2999Assigned T-MOBILE USA, INC. 6529 LOMBARD IL
2018-10-22 331-243-3XXX 3000–3999Assigned T-MOBILE USA, INC. 6529 LOMBARD IL
2018-10-22 331-243-4XXX 4000–4999Assigned T-MOBILE USA, INC. 6529 LOMBARD IL
2018-10-22 331-243-5XXX 5000–5999Assigned T-MOBILE USA, INC. 6529 LOMBARD IL
2018-10-22 331-243-6XXX 6000–6999Assigned T-MOBILE USA, INC. 6529 LOMBARD IL
2018-10-22 331-243-7XXX 7000–7999Assigned T-MOBILE USA, INC. 6529 LOMBARD IL
2018-10-22 331-243-8XXX 8000–8999Assigned T-MOBILE USA, INC. 6529 LOMBARD IL
2018-10-22 331-243-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 LOMBARD IL
2018-10-22 331-246-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 LEMONT IL
2018-10-19 331-219-3XXX 3000–3999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2018-10-17 331-241-0XXX 0000–0999Assigned ONVOY, LLC 224C LOMBARD IL
2018-10-17 331-241-1XXX 1000–1999Assigned ONVOY, LLC 224C LOMBARD IL
2018-10-17 331-241-2XXX 2000–2999Assigned ONVOY, LLC 224C LOMBARD IL
2018-10-12 331-219-1XXX 1000–1999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2018-10-12 331-230-2XXX 2000–2999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2018-10-12 331-230-3XXX 3000–3999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2018-10-12 331-230-4XXX 4000–4999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2018-10-12 331-230-5XXX 5000–5999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2018-10-12 331-230-6XXX 6000–6999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2018-10-12 331-230-7XXX 7000–7999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2018-10-12 331-255-5XXX 5000–5999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2018-10-12 331-255-8XXX 8000–8999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2018-10-12 331-255-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2018-10-10 331-235-9XXX 9000–9999Assigned PEERLESS NETWORK OF ILLINOIS, LLC - IL 063E ST CHARLES IL
2018-10-03 331-219-2XXX 2000–2999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AURORA IL
2018-10-02 331-231-2XXX 2000–2999Assigned PEERLESS NETWORK OF ILLINOIS, LLC - IL 063E NAPERVILLE IL
2018-09-19 331-233-4XXX 4000–4999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 DOWNERSGRV IL
2018-08-28 331-239-0XXX 0000–0999Assigned ONVOY, LLC 224C YORKVILLE IL
2018-08-23 331-704-4XXX 4000–4999Assigned ONVOY, LLC 224C KANEVILLE IL
2018-08-21 331-704-7XXX 7000–7999Assigned PEERLESS NETWORK OF ILLINOIS, LLC - IL 063E KANEVILLE IL
2018-07-25 331-235-7XXX 7000–7999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E ST CHARLES IL
2018-07-19 331-230-1XXX 1000–1999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AURORA IL
2018-07-19 331-231-5XXX 5000–5999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NAPERVILLE IL
2018-06-21 331-227-4XXX 4000–4999Assigned ONVOY, LLC 224C SUGARGROVE IL
2018-06-18 331-303-9XXX 9000–9999Assigned TELNYX LLC 073H ELBURN IL
2018-06-18 331-704-8XXX 8000–8999Assigned TELNYX LLC 073H KANEVILLE IL
2018-06-18 331-808-8XXX 8000–8999Assigned TELNYX LLC 073H PLANO IL
2018-06-15 331-219-5XXX 5000–5999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AURORA IL
2018-06-15 331-231-7XXX 7000–7999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 NAPERVILLE IL
2018-06-15 331-231-8XXX 8000–8999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 NAPERVILLE IL
2018-06-08 331-227-5XXX 5000–5999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E SUGARGROVE IL
2018-06-08 331-234-9XXX 9000–9999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E SUGARGROVE IL
2018-04-26 331-245-2XXX 2000–2999Assigned PEERLESS NETWORK OF ILLINOIS, LLC - IL 063E BARTLETT IL
2018-04-12 331-238-2XXX 2000–2999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 DOWNERSGRV 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.