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 |
|---|---|---|---|---|---|---|---|
| 2015-09-16 | 831-741-7XXX | 7000–7999 | Assigned | CENTURYLINK COMMUNICATIONS, LLC | 508J | CASTROVL | CA |
| 2015-09-15 | 831-256-8XXX | 8000–8999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2015-09-15 | 831-256-9XXX | 9000–9999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2015-09-08 | 831-226-6XXX | 6000–6999 | Assigned | T-MOBILE USA, INC. | 6529 | SANTA CRUZ | CA |
| 2015-09-03 | 831-319-9XXX | 9000–9999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | WATSONVL | CA |
| 2015-08-24 | 831-582-1XXX | 1000–1999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | MONTEREY | CA |
| 2015-08-17 | 831-219-2XXX | 2000–2999 | Assigned | ONVOY, LLC - CA | 649C | APTOS | CA |
| 2015-08-17 | 831-226-7XXX | 7000–7999 | Assigned | ONVOY, LLC - CA | 649C | SANTA CRUZ | CA |
| 2015-08-17 | 831-226-8XXX | 8000–8999 | Assigned | ONVOY, LLC - CA | 649C | SANTA CRUZ | CA |
| 2015-08-17 | 831-246-9XXX | 9000–9999 | Assigned | ONVOY, LLC - CA | 649C | BEN LOMOND | CA |
| 2015-08-17 | 831-534-9XXX | 9000–9999 | Assigned | ONVOY, LLC - CA | 649C | FELTON | CA |
| 2015-08-17 | 831-777-7XXX | 7000–7999 | Assigned | ONVOY, LLC - CA | 649C | SANTA CRUZ | CA |
| 2015-08-17 | 831-777-8XXX | 8000–8999 | Assigned | ONVOY, LLC - CA | 649C | SANTA CRUZ | CA |
| 2015-08-17 | 831-777-9XXX | 9000–9999 | Assigned | ONVOY, LLC - CA | 649C | SANTA CRUZ | CA |
| 2015-08-12 | 831-226-0XXX | 0000–0999 | Assigned | IP HORIZON LLC | 515J | SANTA CRUZ | CA |
| 2015-08-10 | 831-226-9XXX | 9000–9999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | SANTA CRUZ | CA |
| 2015-07-29 | 831-226-2XXX | 2000–2999 | Assigned | COMCAST PHONE OF CALIFORNIA, LLC | 394L | SANTA CRUZ | CA |
| 2015-07-29 | 831-796-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | SALINAS | CA |
| 2015-07-17 | 831-703-8XXX | 8000–8999 | Assigned | ONVOY, LLC - CA | 649C | BOULDERCRK | CA |
| 2015-07-17 | 831-703-9XXX | 9000–9999 | Assigned | ONVOY, LLC - CA | 649C | BOULDERCRK | CA |
| 2015-07-16 | 831-226-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | SANTA CRUZ | CA |
| 2015-07-15 | 831-406-5XXX | 5000–5999 | Assigned | ONVOY, LLC - CA | 649C | WATSONVL | CA |
| 2015-07-15 | 831-539-0XXX | 0000–0999 | Assigned | ONVOY, LLC - CA | 649C | WATSONVL | CA |
| 2015-07-15 | 831-574-8XXX | 8000–8999 | Assigned | COMCAST PHONE OF CALIFORNIA, LLC | 394L | CARMEL | CA |
| 2015-07-15 | 831-704-5XXX | 5000–5999 | Assigned | ONVOY, LLC - CA | 649C | FELTON | CA |
| 2015-07-15 | 831-704-9XXX | 9000–9999 | Assigned | ONVOY, LLC - CA | 649C | FELTON | CA |
| 2015-07-15 | 831-708-0XXX | 0000–0999 | Assigned | ONVOY, LLC - CA | 649C | APTOS | CA |
| 2015-07-15 | 831-709-9XXX | 9000–9999 | Assigned | ONVOY, LLC - CA | 649C | BEN LOMOND | CA |
| 2015-07-08 | 831-291-8XXX | 8000–8999 | Assigned | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | SANTA CRUZ | CA |
| 2015-07-01 | 831-256-3XXX | 3000–3999 | Assigned | TWILIO INTERNATIONAL, INC. | 506J | SALINAS | CA |
| 2015-07-01 | 831-256-4XXX | 4000–4999 | Assigned | IP HORIZON LLC | 515J | SALINAS | CA |
| 2015-06-29 | 831-574-1XXX | 1000–1999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | CARMEL | CA |
| 2015-06-23 | 831-225-7XXX | 7000–7999 | Assigned | CENTURYLINK COMMUNICATIONS, LLC | 508J | SALINAS | CA |
| 2015-06-22 | 831-256-5XXX | 5000–5999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2015-06-22 | 831-256-6XXX | 6000–6999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2015-06-19 | 831-726-0XXX | 0000–0999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | WATSONVL | CA |
| 2015-06-19 | 831-750-3XXX | 3000–3999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | WATSONVL | CA |
| 2015-06-18 | 831-337-8XXX | 8000–8999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | BOULDERCRK | CA |
| 2015-06-17 | 831-346-3XXX | 3000–3999 | Assigned | ONVOY, LLC - CA | 649C | SANTA CRUZ | CA |
| 2015-06-17 | 831-346-4XXX | 4000–4999 | Assigned | ONVOY, LLC - CA | 649C | SANTA CRUZ | CA |
| 2015-06-11 | 831-726-5XXX | 5000–5999 | Assigned | AT&T ENTERPRISES, LLC | 516C | WATSONVL | CA |
| 2015-06-09 | 831-346-2XXX | 2000–2999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | SANTA CRUZ | CA |
| 2015-06-05 | 831-346-8XXX | 8000–8999 | Assigned | T-MOBILE USA, INC. | 6529 | SANTA CRUZ | CA |
| 2015-06-03 | 831-319-5XXX | 5000–5999 | Assigned | ONVOY, LLC - CA | 649C | WATSONVL | CA |
| 2015-06-03 | 831-704-1XXX | 1000–1999 | Assigned | ONVOY, LLC - CA | 649C | FELTON | CA |
| 2015-06-02 | 831-920-9XXX | 9000–9999 | Assigned | NEW CINGULAR WIRELESS PCS, LLC | 6010 | MONTEREY | CA |
| 2015-05-26 | 831-200-1XXX | 1000–1999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | MONTEREY | CA |
| 2015-05-26 | 831-200-3XXX | 3000–3999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | MONTEREY | CA |
| 2015-05-26 | 831-200-4XXX | 4000–4999 | Assigned | BANDWIDTH.COM CLEC, LLC - CA | 981E | MONTEREY | CA |
| 2015-05-18 | 831-265-2XXX | 2000–2999 | 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.