NumberResearchRecent thousands-block assignments
13 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 831
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 |
|---|---|---|---|---|---|---|---|
| 2015-04-20 | 831-406-8XXX | 8000–8999 | Assigned | T-MOBILE USA, INC. | 6529 | WATSONVL | CA |
| 2015-04-20 | 831-661-9XXX | 9000–9999 | Assigned | ONVOY, LLC - CA | 649C | APTOS | CA |
| 2015-04-16 | 831-346-1XXX | 1000–1999 | Assigned | ONVOY, LLC - CA | 649C | SANTA CRUZ | CA |
| 2015-04-16 | 831-750-1XXX | 1000–1999 | Assigned | ONVOY, LLC - CA | 649C | WATSONVL | CA |
| 2015-04-07 | 831-350-3XXX | 3000–3999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | TRES PINOS | CA |
| 2015-04-06 | 831-382-6XXX | 6000–6999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | SAN LUCAS | CA |
| 2015-04-06 | 831-652-8XXX | 8000–8999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | CARMEL VLY | CA |
| 2015-04-06 | 831-856-3XXX | 3000–3999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | GREENFIELD | CA |
| 2015-04-03 | 831-948-0XXX | 0000–0999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | WATSONVL | CA |
| 2015-04-03 | 831-948-1XXX | 1000–1999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | WATSONVL | CA |
| 2015-04-03 | 831-948-2XXX | 2000–2999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | WATSONVL | CA |
| 2015-04-03 | 831-948-3XXX | 3000–3999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | WATSONVL | CA |
| 2015-04-03 | 831-948-4XXX | 4000–4999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | WATSONVL | CA |
| 2015-04-03 | 831-948-5XXX | 5000–5999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | WATSONVL | CA |
| 2015-04-03 | 831-948-6XXX | 6000–6999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | WATSONVL | CA |
| 2015-04-03 | 831-948-7XXX | 7000–7999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | WATSONVL | CA |
| 2015-04-03 | 831-948-8XXX | 8000–8999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | WATSONVL | CA |
| 2015-04-03 | 831-948-9XXX | 9000–9999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | WATSONVL | CA |
| 2015-04-01 | 831-525-4XXX | 4000–4999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | KING CITY | CA |
| 2015-04-01 | 831-789-2XXX | 2000–2999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | SALINAS | CA |
| 2015-03-30 | 831-586-8XXX | 8000–8999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | SAN JUAN | CA |
| 2015-03-30 | 831-740-0XXX | 0000–0999 | Assigned | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | WATSONVL | CA |
| 2015-03-27 | 831-610-8XXX | 8000–8999 | Assigned | COMCAST PHONE OF CALIFORNIA, LLC | 394L | BOULDERCRK | CA |
| 2015-03-26 | 831-821-4XXX | 4000–4999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | TRES PINOS | CA |
| 2015-03-13 | 831-704-2XXX | 2000–2999 | Assigned | COMCAST PHONE OF CALIFORNIA, LLC | 394L | FELTON | CA |
| 2015-03-05 | 831-324-2XXX | 2000–2999 | Assigned | T-MOBILE USA, INC. | 6529 | MONTEREY | CA |
| 2015-03-05 | 831-324-8XXX | 8000–8999 | Assigned | T-MOBILE USA, INC. | 6529 | MONTEREY | CA |
| 2015-03-03 | 831-512-0XXX | 0000–0999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2015-03-03 | 831-783-6XXX | 6000–6999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2015-03-03 | 831-783-7XXX | 7000–7999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2015-03-03 | 831-800-4XXX | 4000–4999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2015-02-18 | 831-498-6XXX | 6000–6999 | Assigned | T-MOBILE USA, INC. | 6529 | WATSONVL | CA |
| 2015-02-18 | 831-498-8XXX | 8000–8999 | Assigned | T-MOBILE USA, INC. | 6529 | WATSONVL | CA |
| 2015-02-17 | 831-346-7XXX | 7000–7999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | SANTA CRUZ | CA |
| 2015-02-16 | 831-237-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA | 7240 | SOLEDAD | CA |
| 2015-01-28 | 831-232-6XXX | 6000–6999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | CHUALAR | CA |
| 2015-01-28 | 831-453-0XXX | 0000–0999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | CASTROVL | CA |
| 2015-01-28 | 831-508-8XXX | 8000–8999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | FELTON | CA |
| 2015-01-28 | 831-508-9XXX | 9000–9999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | FELTON | CA |
| 2015-01-23 | 831-313-2XXX | 2000–2999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | HOLLISTER | CA |
| 2015-01-23 | 831-313-4XXX | 4000–4999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | HOLLISTER | CA |
| 2014-12-10 | 831-200-2XXX | 2000–2999 | Assigned | PEERLESS NETWORK OF CALIFORNIA, LLC - CA | 373F | MONTEREY | CA |
| 2014-12-01 | 831-200-0XXX | 0000–0999 | Assigned | PEERLESS NETWORK OF CALIFORNIA, LLC - CA | 373F | MONTEREY | CA |
| 2014-11-24 | 831-718-8XXX | 8000–8999 | Assigned | COMCAST PHONE OF CALIFORNIA, LLC | 394L | MONTEREY | CA |
| 2014-11-07 | 831-287-4XXX | 4000–4999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | SALINAS | CA |
| 2014-10-29 | 831-800-5XXX | 5000–5999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2014-10-29 | 831-975-1XXX | 1000–1999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2014-10-29 | 831-975-3XXX | 3000–3999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2014-10-24 | 831-313-7XXX | 7000–7999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
| 2014-10-24 | 831-313-8XXX | 8000–8999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
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.