NumberResearchRecent thousands-block assignments
11 blocks assigned in the last 30 days · from the daily NANPA thousands-block report, 09/20/2026
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
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
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2015-08-03 | 331-307-7XXX | 7000–7999 | Assigned | COMCAST IP PHONE, LLC | 318J | LOMBARD | IL |
| 2015-07-30 | 331-307-0XXX | 0000–0999 | Assigned | ONVOY, LLC | 224C | LOMBARD | IL |
| 2015-07-30 | 331-814-2XXX | 2000–2999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | NAPERVILLE | IL |
| 2015-07-28 | 331-301-2XXX | 2000–2999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - IL | 6115 | AURORA | IL |
| 2015-07-23 | 331-321-9XXX | 9000–9999 | Assigned | T-MOBILE USA, INC. | 6529 | AURORA | IL |
| 2015-07-15 | 331-301-6XXX | 6000–6999 | Assigned | T-MOBILE USA, INC. | 6529 | AURORA | IL |
| 2015-07-15 | 331-980-0XXX | 0000–0999 | Assigned | T-MOBILE USA, INC. | 6529 | AURORA | IL |
| 2015-07-15 | 331-980-1XXX | 1000–1999 | Assigned | T-MOBILE USA, INC. | 6529 | AURORA | IL |
| 2015-07-14 | 331-302-8XXX | 8000–8999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL | 6333 | AURORA | IL |
| 2015-07-10 | 331-903-4XXX | 4000–4999 | Assigned | TELEPORT COMMUNICATIONS AMERICA, LLC - IL | 7136 | DOWNERSGRV | IL |
| 2015-06-26 | 331-814-5XXX | 5000–5999 | Assigned | T-MOBILE USA, INC. | 6529 | NAPERVILLE | IL |
| 2015-06-26 | 331-814-9XXX | 9000–9999 | Assigned | T-MOBILE USA, INC. | 6529 | NAPERVILLE | IL |
| 2015-06-25 | 331-903-9XXX | 9000–9999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | DOWNERSGRV | IL |
| 2015-06-23 | 331-301-5XXX | 5000–5999 | Assigned | COMCAST IP PHONE, LLC | 318J | AURORA | IL |
| 2015-06-23 | 331-901-8XXX | 8000–8999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | ST CHARLES | IL |
| 2015-06-23 | 331-901-9XXX | 9000–9999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC - IL | 6534 | ST CHARLES | IL |
| 2015-06-22 | 331-701-1XXX | 1000–1999 | Assigned | T-MOBILE USA, INC. | 6529 | NAPERVILLE | IL |
| 2015-06-22 | 331-701-8XXX | 8000–8999 | Assigned | T-MOBILE USA, INC. | 6529 | NAPERVILLE | IL |
| 2015-06-22 | 331-701-9XXX | 9000–9999 | Assigned | T-MOBILE USA, INC. | 6529 | NAPERVILLE | IL |
| 2015-06-18 | 331-806-1XXX | 1000–1999 | Assigned | FIRST COMMUNICATIONS, LLC | 460K | WHEATON | IL |
| 2015-06-12 | 331-806-3XXX | 3000–3999 | Assigned | COMCAST IP PHONE, LLC | 318J | WHEATON | IL |
| 2015-06-09 | 331-254-1XXX | 1000–1999 | Assigned | BANDWIDTH.COM CLEC, LLC - IL | 984E | SUGARGROVE | IL |
| 2015-06-09 | 331-903-3XXX | 3000–3999 | Assigned | COMCAST IP PHONE, LLC | 318J | DOWNERSGRV | IL |
| 2015-06-09 | 331-979-1XXX | 1000–1999 | Assigned | BANDWIDTH.COM CLEC, LLC - IL | 984E | ELMHURST | IL |
| 2015-06-08 | 331-808-0XXX | 0000–0999 | Assigned | BANDWIDTH.COM CLEC, LLC - IL | 984E | PLANO | IL |
| 2015-06-02 | 331-253-2XXX | 2000–2999 | Assigned | BANDWIDTH.COM CLEC, LLC - IL | 984E | LEMONT | IL |
| 2015-05-28 | 331-310-1XXX | 1000–1999 | Assigned | PEERLESS NETWORK OF ILLINOIS, LLC - IL | 063E | BIG ROCK | IL |
| 2015-05-12 | 331-888-9XXX | 9000–9999 | Assigned | PEERLESS NETWORK OF ILLINOIS, LLC - IL | 063E | WARRENVL | IL |
| 2015-04-28 | 331-901-0XXX | 0000–0999 | Assigned | BANDWIDTH.COM CLEC, LLC - IL | 984E | ST CHARLES | IL |
| 2015-04-23 | 331-704-0XXX | 0000–0999 | Assigned | BANDWIDTH.COM CLEC, LLC - IL | 984E | KANEVILLE | IL |
| 2015-04-22 | 331-701-5XXX | 5000–5999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL | 6333 | NAPERVILLE | IL |
| 2015-04-22 | 331-701-6XXX | 6000–6999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL | 6333 | NAPERVILLE | IL |
| 2015-04-17 | 331-276-2XXX | 2000–2999 | Assigned | BANDWIDTH.COM CLEC, LLC - IL | 984E | ST CHARLES | IL |
| 2015-04-16 | 331-303-5XXX | 5000–5999 | Assigned | BANDWIDTH.COM CLEC, LLC - IL | 984E | ELBURN | IL |
| 2015-04-16 | 331-303-6XXX | 6000–6999 | Assigned | BANDWIDTH.COM CLEC, LLC - IL | 984E | ELBURN | IL |
| 2015-04-16 | 331-303-8XXX | 8000–8999 | Assigned | BANDWIDTH.COM CLEC, LLC - IL | 984E | ELBURN | IL |
| 2015-04-16 | 331-701-7XXX | 7000–7999 | Assigned | COMCAST IP PHONE, LLC | 318J | NAPERVILLE | IL |
| 2015-04-03 | 331-701-2XXX | 2000–2999 | Assigned | ONVOY, LLC | 224C | NAPERVILLE | IL |
| 2015-03-27 | 331-980-2XXX | 2000–2999 | Assigned | T-MOBILE USA, INC. | 6529 | AURORA | IL |
| 2015-03-27 | 331-980-3XXX | 3000–3999 | Assigned | T-MOBILE USA, INC. | 6529 | AURORA | IL |
| 2015-03-27 | 331-980-4XXX | 4000–4999 | Assigned | T-MOBILE USA, INC. | 6529 | AURORA | IL |
| 2015-03-27 | 331-980-5XXX | 5000–5999 | Assigned | T-MOBILE USA, INC. | 6529 | AURORA | IL |
| 2015-03-27 | 331-980-6XXX | 6000–6999 | Assigned | T-MOBILE USA, INC. | 6529 | AURORA | IL |
| 2015-03-24 | 331-216-5XXX | 5000–5999 | Assigned | COMCAST IP PHONE, LLC | 318J | OSWEGO | IL |
| 2015-03-05 | 331-979-0XXX | 0000–0999 | Assigned | COMCAST IP PHONE, LLC | 318J | ELMHURST | IL |
| 2015-03-05 | 331-979-2XXX | 2000–2999 | Assigned | COMCAST IP PHONE, LLC | 318J | ELMHURST | IL |
| 2015-02-23 | 331-304-8XXX | 8000–8999 | Assigned | T-MOBILE USA, INC. | 6529 | BARTLETT | IL |
| 2015-02-23 | 331-304-9XXX | 9000–9999 | Assigned | T-MOBILE USA, INC. | 6529 | BARTLETT | IL |
| 2015-02-17 | 331-308-3XXX | 3000–3999 | Assigned | T-MOBILE USA, INC. | 6529 | BARTLETT | IL |
| 2015-02-17 | 331-308-4XXX | 4000–4999 | Assigned | T-MOBILE USA, INC. | 6529 | BARTLETT | 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.