NumberResearchRecent prefix assignments
0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026
The Code holder is who opened each NPA-NXX prefix — not necessarily who holds the numbers. A prefix is 10,000 numbers, but under pooling its ten 1,000-number blocks are handed out individually, often to different carriers; the code holder may hold only one block, or none. The Thousands-blocks column shows how the ten blocks are really split — click which blocks → to see who holds each 1,000-number block and its last-4-digit range. Assignments are initial assignments; the current serving carrier may differ due to portability.
| Assigned | NPA-NXX | Thousands-blocks taken (last-4 opening) | Code holder | OCN | Rate center | State |
|---|---|---|---|---|---|---|
| 2025-11-28 | 341-265 | 0XXX1XXX2XXX3XXX8XXX9XXX · 3 holders which blocks → | T-MOBILE USA, INC. | 6529 | ELSBR-PINL | CA |
| 2024-11-14 | 341-259 | 0–9 XXXall 10 · 2 holders which blocks → | T-MOBILE USA, INC. | 6529 | ELSBR-PINL | CA |
| 2024-09-12 | 341-256 | 0XXX1XXX2XXX3XXX4XXX7XXX8XXX9XXX · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | OKLD FRTVL | CA |
| 2024-09-09 | 341-254 | 0–9 XXXall 10 · 6 holders which blocks → | T-MOBILE USA, INC. | 6529 | OKLD BKLY | CA |
| 2024-05-31 | 341-252 | 0–9 XXXall 10 · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | FRNK MAIN | CA |
| 2024-03-27 | 341-251 | 0–9 XXXall 10 · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | ELSBR-PINL | CA |
| 2024-01-23 | 341-244 | 0–9 XXXall 10 · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | OKLD TRNID | CA |
| 2023-11-08 | 341-242 | 0–9 XXXall 10 · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | RICHMOND | CA |
| 2023-11-01 | 341-240 | 0–9 XXXall 10 · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | HAYWARD | CA |
| 2023-05-08 | 341-231 | 0–9 XXXall 10 · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | ELSBR-PINL | CA |
| 2022-02-28 | 341-221 | 0–9 XXXall 10 · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | HAYWARD | CA |
| 2022-01-10 | 341-213 | 0–9 XXXall 10 · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | OKLD MN-PD | CA |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.