NumberResearchRecent thousands-block assignments
0 blocks assigned in the last 30 days · from the daily NANPA thousands-block report, 09/24/2026
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, all time — 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 |
|---|---|---|---|---|---|---|---|
| 2025-12-03 | 831-327-7XXX | 7000–7999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
| 2025-09-24 | 831-327-2XXX | 2000–2999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
| 2025-07-10 | 831-327-3XXX | 3000–3999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
| 2025-04-25 | 831-327-1XXX | 1000–1999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
| 2025-01-07 | 831-327-8XXX | 8000–8999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
| 2024-08-19 | 831-312-6XXX | 6000–6999 | Assigned | T-MOBILE USA, INC. | 6529 | MONTEREY | CA |
| 2024-07-29 | 831-665-4XXX | 4000–4999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
| 2023-12-04 | 831-664-4XXX | 4000–4999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
| 2023-12-04 | 831-664-5XXX | 5000–5999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
| 2023-09-29 | 831-867-1XXX | 1000–1999 | Assigned | T-MOBILE USA, INC. | 6529 | MONTEREY | CA |
| 2023-09-29 | 831-867-2XXX | 2000–2999 | Assigned | T-MOBILE USA, INC. | 6529 | MONTEREY | CA |
| 2023-08-15 | 831-869-4XXX | 4000–4999 | Assigned | T-MOBILE USA, INC. | 6529 | MONTEREY | CA |
| 2023-07-12 | 831-833-5XXX | 5000–5999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
| 2023-05-08 | 831-833-6XXX | 6000–6999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
| 2022-09-19 | 831-833-9XXX | 9000–9999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
| 2021-10-28 | 831-665-9XXX | 9000–9999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
| 2021-10-01 | 831-220-1XXX | 1000–1999 | Assigned | T-MOBILE USA, INC. | 6529 | MONTEREY | CA |
| 2021-06-30 | 831-785-6XXX | 6000–6999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2021-06-30 | 831-785-8XXX | 8000–8999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2021-04-16 | 831-902-1XXX | 1000–1999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
| 2021-04-16 | 831-902-3XXX | 3000–3999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
| 2021-03-24 | 831-266-5XXX | 5000–5999 | Assigned | T-MOBILE USA, INC. | 6529 | SANTA CRUZ | CA |
| 2021-03-24 | 831-266-6XXX | 6000–6999 | Assigned | T-MOBILE USA, INC. | 6529 | SANTA CRUZ | CA |
| 2021-03-24 | 831-266-7XXX | 7000–7999 | Assigned | T-MOBILE USA, INC. | 6529 | SANTA CRUZ | CA |
| 2021-03-24 | 831-266-8XXX | 8000–8999 | Assigned | T-MOBILE USA, INC. | 6529 | SANTA CRUZ | CA |
| 2021-03-24 | 831-266-9XXX | 9000–9999 | Assigned | T-MOBILE USA, INC. | 6529 | SANTA CRUZ | CA |
| 2021-03-22 | 831-576-7XXX | 7000–7999 | Assigned | T-MOBILE USA, INC. | 6529 | SANTA CRUZ | CA |
| 2021-03-22 | 831-621-7XXX | 7000–7999 | Assigned | T-MOBILE USA, INC. | 6529 | SANTA CRUZ | CA |
| 2021-03-22 | 831-854-6XXX | 6000–6999 | Assigned | T-MOBILE USA, INC. | 6529 | SANTA CRUZ | CA |
| 2021-03-15 | 831-243-8XXX | 8000–8999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2021-03-15 | 831-243-9XXX | 9000–9999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2021-03-01 | 831-529-4XXX | 4000–4999 | Assigned | T-MOBILE USA, INC. | 6529 | SANTA CRUZ | CA |
| 2021-03-01 | 831-529-5XXX | 5000–5999 | Assigned | T-MOBILE USA, INC. | 6529 | SANTA CRUZ | CA |
| 2021-03-01 | 831-529-6XXX | 6000–6999 | Assigned | T-MOBILE USA, INC. | 6529 | SANTA CRUZ | CA |
| 2021-03-01 | 831-889-3XXX | 3000–3999 | Assigned | T-MOBILE USA, INC. | 6529 | SANTA CRUZ | CA |
| 2021-03-01 | 831-889-9XXX | 9000–9999 | Assigned | T-MOBILE USA, INC. | 6529 | SANTA CRUZ | CA |
| 2021-02-22 | 831-274-0XXX | 0000–0999 | Assigned | T-MOBILE USA, INC. | 6529 | WATSONVL | CA |
| 2021-02-22 | 831-348-1XXX | 1000–1999 | Assigned | T-MOBILE USA, INC. | 6529 | WATSONVL | CA |
| 2021-02-18 | 831-297-9XXX | 9000–9999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
| 2021-02-11 | 831-718-0XXX | 0000–0999 | Assigned | T-MOBILE USA, INC. | 6529 | MONTEREY | CA |
| 2021-01-07 | 831-356-1XXX | 1000–1999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2021-01-07 | 831-356-2XXX | 2000–2999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2020-11-19 | 831-665-3XXX | 3000–3999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
| 2020-10-23 | 831-348-2XXX | 2000–2999 | Assigned | T-MOBILE USA, INC. | 6529 | WATSONVL | CA |
| 2020-10-23 | 831-529-7XXX | 7000–7999 | Assigned | T-MOBILE USA, INC. | 6529 | SANTA CRUZ | CA |
| 2020-09-14 | 831-243-0XXX | 0000–0999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2020-09-14 | 831-243-1XXX | 1000–1999 | Assigned | T-MOBILE USA, INC. | 6529 | SALINAS | CA |
| 2020-07-10 | 831-220-4XXX | 4000–4999 | Assigned | T-MOBILE USA, INC. | 6529 | MONTEREY | CA |
| 2020-07-10 | 831-220-5XXX | 5000–5999 | Assigned | T-MOBILE USA, INC. | 6529 | MONTEREY | CA |
| 2020-07-10 | 831-297-6XXX | 6000–6999 | Assigned | T-MOBILE USA, INC. | 6529 | HOLLISTER | CA |
Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/24/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.