NumberResearchRecent thousands-block assignments
13 blocks assigned in the last 30 days · from the daily NANPA thousands-block report, 09/19/2026
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 |
|---|---|---|---|---|---|---|---|
| 2005-06-28 | 831-428-2XXX | 2000–2999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | SANTA CRUZ | CA |
| 2005-06-28 | 831-524-4XXX | 4000–4999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | HOLLISTER | CA |
| 2005-06-28 | 831-667-5XXX | 5000–5999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | BIG SUR | CA |
| 2005-06-28 | 831-679-3XXX | 3000–3999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | CHUALAR | CA |
| 2005-06-28 | 831-731-5XXX | 5000–5999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | CASTROVL | CA |
| 2005-06-17 | 831-240-5XXX | 5000–5999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | SALINAS | CA |
| 2005-06-17 | 831-455-5XXX | 5000–5999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | SALINAS | CA |
| 2005-06-17 | 831-455-6XXX | 6000–6999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | SALINAS | CA |
| 2005-06-17 | 831-747-4XXX | 4000–4999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | MONTEREY | CA |
| 2005-06-17 | 831-747-7XXX | 7000–7999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | MONTEREY | CA |
| 2005-06-03 | 831-920-4XXX | 4000–4999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | MONTEREY | CA |
| 2005-05-22 | 831-240-8XXX | 8000–8999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | SALINAS | CA |
| 2005-05-22 | 831-240-9XXX | 9000–9999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | SALINAS | CA |
| 2005-05-22 | 831-515-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SANTA CRUZ | CA |
| 2005-05-22 | 831-535-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SANTA CRUZ | CA |
| 2005-05-22 | 831-535-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SANTA CRUZ | CA |
| 2005-05-19 | 831-233-2XXX | 2000–2999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | MONTEREY | CA |
| 2005-05-18 | 831-219-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | APTOS | CA |
| 2005-05-18 | 831-219-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | APTOS | CA |
| 2005-05-18 | 831-532-8XXX | 8000–8999 | Assigned | ONVOY, LLC - CA | 649C | BEN LOMOND | CA |
| 2005-05-18 | 831-532-9XXX | 9000–9999 | Assigned | ONVOY, LLC - CA | 649C | BEN LOMOND | CA |
| 2005-05-18 | 831-533-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | BOULDERCRK | CA |
| 2005-05-18 | 831-533-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | BOULDERCRK | CA |
| 2005-05-18 | 831-533-9XXX | 9000–9999 | Assigned | ONVOY, LLC - CA | 649C | BOULDERCRK | CA |
| 2005-05-18 | 831-534-2XXX | 2000–2999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | FELTON | CA |
| 2005-05-18 | 831-534-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | FELTON | CA |
| 2005-05-18 | 831-534-8XXX | 8000–8999 | Assigned | ONVOY, LLC - CA | 649C | FELTON | CA |
| 2005-05-18 | 831-607-5XXX | 5000–5999 | Assigned | ONVOY, LLC - CA | 649C | APTOS | CA |
| 2005-05-18 | 831-607-6XXX | 6000–6999 | Assigned | ONVOY, LLC - CA | 649C | APTOS | CA |
| 2005-05-18 | 831-607-7XXX | 7000–7999 | Assigned | ONVOY, LLC - CA | 649C | APTOS | CA |
| 2005-05-13 | 831-207-2XXX | 2000–2999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | HOLLISTER | CA |
| 2005-05-13 | 831-331-9XXX | 9000–9999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | SANTA CRUZ | CA |
| 2005-05-13 | 831-431-0XXX | 0000–0999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | SANTA CRUZ | CA |
| 2005-05-13 | 831-431-3XXX | 3000–3999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | SANTA CRUZ | CA |
| 2005-05-11 | 831-536-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WATSONVL | CA |
| 2005-05-11 | 831-536-9XXX | 9000–9999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WATSONVL | CA |
| 2005-04-28 | 831-240-3XXX | 3000–3999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2005-04-21 | 831-531-2XXX | 2000–2999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | APTOS | CA |
| 2005-04-08 | 831-747-1XXX | 1000–1999 | Assigned | AT&T ENTERPRISES, LLC | 516C | MONTEREY | CA |
| 2005-04-05 | 831-776-5XXX | 5000–5999 | Assigned | METROPCS, INC. | 5562 | SALINAS | CA |
| 2005-03-30 | 831-240-1XXX | 1000–1999 | Assigned | METROPCS, INC. | 5562 | SALINAS | CA |
| 2005-03-30 | 831-240-2XXX | 2000–2999 | Assigned | METROPCS, INC. | 5562 | SALINAS | CA |
| 2005-03-30 | 831-580-7XXX | 7000–7999 | Assigned | METROPCS, INC. | 5562 | GONZALES | CA |
| 2005-03-22 | 831-578-8XXX | 8000–8999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | SALINAS | CA |
| 2005-03-22 | 831-917-7XXX | 7000–7999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | MONTEREY | CA |
| 2005-03-10 | 831-241-0XXX | 0000–0999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | MONTEREY | CA |
| 2005-03-10 | 831-241-2XXX | 2000–2999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | MONTEREY | CA |
| 2005-02-18 | 831-585-1XXX | 1000–1999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | SALINAS | CA |
| 2005-02-18 | 831-706-2XXX | 2000–2999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | SANTA CRUZ | CA |
| 2005-02-18 | 831-706-4XXX | 4000–4999 | Assigned | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | SANTA CRUZ | CA |
Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.