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
Clear Download CSV ↓
Recent thousands-block assignments
AssignedThousands-blockLast 4 digitsStatusAssigneeOCNRate centerState
2016-08-24 331-707-8XXX 8000–8999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2016-08-24 331-707-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2016-08-23 331-871-1XXX 1000–1999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 W CHICAGO IL
2016-08-19 331-204-9XXX 9000–9999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 NAPERVILLE IL
2016-08-18 331-300-7XXX 7000–7999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2016-08-18 331-321-5XXX 5000–5999Assigned T-MOBILE USA, INC. 6529 AURORA IL
2016-08-12 331-775-5XXX 5000–5999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 DOWNERSGRV IL
2016-08-11 331-315-9XXX 9000–9999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LOMBARD IL
2016-08-11 331-757-5XXX 5000–5999Assigned COMCAST IP PHONE, LLC 318J LEMONT IL
2016-08-04 331-300-4XXX 4000–4999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AURORA IL
2016-08-04 331-300-5XXX 5000–5999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 AURORA IL
2016-08-04 331-300-6XXX 6000–6999Assigned TELEPORT COMMUNICATIONS AMERICA, LLC - IL 7136 AURORA IL
2016-07-22 331-717-8XXX 8000–8999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 OSWEGO IL
2016-07-19 331-300-3XXX 3000–3999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E AURORA IL
2016-07-19 331-716-9XXX 9000–9999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E WHEATON IL
2016-07-18 331-716-7XXX 7000–7999Assigned COMCAST IP PHONE, LLC 318J WHEATON IL
2016-07-13 331-757-8XXX 8000–8999Assigned T-MOBILE USA, INC. 6529 LEMONT IL
2016-07-13 331-757-9XXX 9000–9999Assigned T-MOBILE USA, INC. 6529 LEMONT IL
2016-07-13 331-814-6XXX 6000–6999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NAPERVILLE IL
2016-07-13 331-814-7XXX 7000–7999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NAPERVILLE IL
2016-07-11 331-204-8XXX 8000–8999Assigned IP HORIZON LLC 515J NAPERVILLE IL
2016-07-11 331-300-8XXX 8000–8999Assigned IP HORIZON LLC 515J AURORA IL
2016-07-11 331-307-6XXX 6000–6999Assigned IP HORIZON LLC 515J LOMBARD IL
2016-07-11 331-716-8XXX 8000–8999Assigned IP HORIZON LLC 515J WHEATON IL
2016-07-11 331-771-6XXX 6000–6999Assigned IP HORIZON LLC 515J ST CHARLES IL
2016-07-11 331-803-9XXX 9000–9999Assigned IP HORIZON LLC 515J LEMONT IL
2016-07-11 331-979-8XXX 8000–8999Assigned IP HORIZON LLC 515J ELMHURST IL
2016-07-08 331-253-7XXX 7000–7999Assigned T-MOBILE USA, INC. 6529 LEMONT IL
2016-06-21 331-204-5XXX 5000–5999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E NAPERVILLE IL
2016-06-21 331-252-0XXX 0000–0999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E WARRENVL IL
2016-06-21 331-253-6XXX 6000–6999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E LEMONT IL
2016-06-21 331-300-2XXX 2000–2999Assigned COMCAST IP PHONE, LLC 318J AURORA IL
2016-06-21 331-717-3XXX 3000–3999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E OSWEGO IL
2016-06-21 331-871-0XXX 0000–0999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E W CHICAGO IL
2016-06-21 331-979-6XXX 6000–6999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E ELMHURST IL
2016-06-15 331-300-1XXX 1000–1999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 AURORA IL
2016-06-15 331-771-1XXX 1000–1999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 ST CHARLES IL
2016-06-15 331-808-3XXX 3000–3999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E PLANO IL
2016-06-14 331-300-0XXX 0000–0999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E AURORA IL
2016-06-14 331-716-0XXX 0000–0999Assigned BANDWIDTH.COM CLEC, LLC - IL 984E WHEATON IL
2016-06-02 331-252-6XXX 6000–6999Assigned TELEPORT COMMUNICATIONS AMERICA, LLC - IL 7136 WARRENVL IL
2016-06-01 331-903-1XXX 1000–1999Assigned FIRST COMMUNICATIONS, LLC 460K DOWNERSGRV IL
2016-05-20 331-401-4XXX 4000–4999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NAPERVILLE IL
2016-05-18 331-227-0XXX 0000–0999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 SUGARGROVE IL
2016-05-18 331-806-4XXX 4000–4999Assigned TELEPORT COMMUNICATIONS AMERICA, LLC - IL 7136 WHEATON IL
2016-05-06 331-771-0XXX 0000–0999Assigned CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 6333 ST CHARLES IL
2016-04-29 331-717-2XXX 2000–2999Assigned ONVOY, LLC 224C OSWEGO IL
2016-04-22 331-775-8XXX 8000–8999Assigned NEW CINGULAR WIRELESS PCS, LLC - IL 6534 DOWNERSGRV IL
2016-04-01 331-204-3XXX 3000–3999Assigned ONVOY, LLC 224C NAPERVILLE IL
2016-04-01 331-204-4XXX 4000–4999Assigned ONVOY, LLC 224C NAPERVILLE 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.