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 |
|---|---|---|---|---|---|---|---|
| 2018-06-28 | 831-889-7XXX | 7000–7999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | SANTA CRUZ | CA |
| 2018-06-22 | 831-679-9XXX | 9000–9999 | Assigned | CHARTER IP ENABLED SERVICES, LLC | 792K | CHUALAR | CA |
| 2018-06-21 | 831-221-3XXX | 3000–3999 | Assigned | TELNYX LLC | 073H | SAN ARDO | CA |
| 2018-06-21 | 831-232-3XXX | 3000–3999 | Assigned | TELNYX LLC | 073H | CHUALAR | CA |
| 2018-06-21 | 831-298-4XXX | 4000–4999 | Assigned | TELNYX LLC | 073H | CARMEL VLY | CA |
| 2018-06-21 | 831-300-2XXX | 2000–2999 | Assigned | TELNYX LLC | 073H | BIG SUR | CA |
| 2018-06-21 | 831-302-1XXX | 1000–1999 | Assigned | TELNYX LLC | 073H | SAN LUCAS | CA |
| 2018-06-21 | 831-315-4XXX | 4000–4999 | Assigned | TELNYX LLC | 073H | SOLEDAD | CA |
| 2018-06-21 | 831-525-7XXX | 7000–7999 | Assigned | TELNYX LLC | 073H | KING CITY | CA |
| 2018-06-21 | 831-613-8XXX | 8000–8999 | Assigned | TELNYX LLC | 073H | GREENFIELD | CA |
| 2018-06-21 | 831-623-8XXX | 8000–8999 | Assigned | TELNYX LLC | 073H | SAN JUAN | CA |
| 2018-06-21 | 831-731-3XXX | 3000–3999 | Assigned | TELNYX LLC | 073H | CASTROVL | CA |
| 2018-06-21 | 831-821-5XXX | 5000–5999 | Assigned | TELNYX LLC | 073H | TRES PINOS | CA |
| 2018-06-08 | 831-717-8XXX | 8000–8999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | MONTEREY | CA |
| 2018-06-05 | 831-718-2XXX | 2000–2999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA | 7240 | MONTEREY | CA |
| 2018-06-01 | 831-220-0XXX | 0000–0999 | Assigned | VONAGE AMERICA LLC | 197D | MONTEREY | CA |
| 2018-05-29 | 831-386-1XXX | 1000–1999 | Assigned | CHARTER IP ENABLED SERVICES, LLC | 792K | KING CITY | CA |
| 2018-05-23 | 831-315-3XXX | 3000–3999 | Assigned | CHARTER IP ENABLED SERVICES, LLC | 792K | SOLEDAD | CA |
| 2018-05-11 | 831-315-8XXX | 8000–8999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | SOLEDAD | CA |
| 2018-05-08 | 831-276-2XXX | 2000–2999 | Assigned | METROPCS, INC. | 5562 | SALINAS | CA |
| 2018-05-08 | 831-276-8XXX | 8000–8999 | Assigned | METROPCS, INC. | 5562 | SALINAS | CA |
| 2018-05-08 | 831-276-9XXX | 9000–9999 | Assigned | METROPCS, INC. | 5562 | SALINAS | CA |
| 2018-05-08 | 831-500-3XXX | 3000–3999 | Assigned | METROPCS, INC. | 5562 | SALINAS | CA |
| 2018-05-08 | 831-500-4XXX | 4000–4999 | Assigned | METROPCS, INC. | 5562 | SALINAS | CA |
| 2018-05-08 | 831-789-0XXX | 0000–0999 | Assigned | METROPCS, INC. | 5562 | SALINAS | CA |
| 2018-05-08 | 831-789-1XXX | 1000–1999 | Assigned | METROPCS, INC. | 5562 | SALINAS | CA |
| 2018-04-04 | 831-500-7XXX | 7000–7999 | Assigned | METROPCS, INC. | 5562 | SALINAS | CA |
| 2018-04-04 | 831-500-8XXX | 8000–8999 | Assigned | METROPCS, INC. | 5562 | SALINAS | CA |
| 2018-04-04 | 831-500-9XXX | 9000–9999 | Assigned | METROPCS, INC. | 5562 | SALINAS | CA |
| 2018-04-04 | 831-666-8XXX | 8000–8999 | Assigned | METROPCS, INC. | 5562 | WATSONVL | CA |
| 2018-04-04 | 831-666-9XXX | 9000–9999 | Assigned | METROPCS, INC. | 5562 | WATSONVL | CA |
| 2018-04-02 | 831-202-9XXX | 9000–9999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SALINAS | CA |
| 2018-02-13 | 831-537-1XXX | 1000–1999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | HOLLISTER | CA |
| 2018-02-12 | 831-315-9XXX | 9000–9999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | SOLEDAD | CA |
| 2018-02-12 | 831-593-9XXX | 9000–9999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | SAN JUAN | CA |
| 2018-02-12 | 831-705-9XXX | 9000–9999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | CHUALAR | CA |
| 2018-02-02 | 831-673-3XXX | 3000–3999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | HOLLISTER | CA |
| 2018-01-31 | 831-744-6XXX | 6000–6999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | GONZALES | CA |
| 2018-01-17 | 831-500-1XXX | 1000–1999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | SALINAS | CA |
| 2018-01-17 | 831-500-2XXX | 2000–2999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | SALINAS | CA |
| 2017-12-19 | 831-400-2XXX | 2000–2999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | SANTA CRUZ | CA |
| 2017-12-19 | 831-400-6XXX | 6000–6999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | SANTA CRUZ | CA |
| 2017-12-06 | 831-572-5XXX | 5000–5999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | APTOS | CA |
| 2017-11-30 | 831-572-0XXX | 0000–0999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | APTOS | CA |
| 2017-11-30 | 831-572-1XXX | 1000–1999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | APTOS | CA |
| 2017-11-30 | 831-572-2XXX | 2000–2999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | APTOS | CA |
| 2017-11-30 | 831-572-3XXX | 3000–3999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | APTOS | CA |
| 2017-11-30 | 831-572-4XXX | 4000–4999 | Assigned | UTILITY TELECOM GROUP, LLC - CA | 9262 | APTOS | CA |
| 2017-11-30 | 831-665-2XXX | 2000–2999 | Assigned | METROPCS, INC. | 5562 | HOLLISTER | CA |
| 2017-10-10 | 831-400-7XXX | 7000–7999 | Assigned | T-MOBILE USA, INC. | 6529 | SANTA CRUZ | 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.