NumberResearchRecent prefix assignments
0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026
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 |
|---|---|---|---|---|---|---|
| 2018-10-18 | 870-517 | 0–9 XXXall 10 · 3 holders which blocks → | T-MOBILE USA, INC. | 6529 | HARRISON | AR |
| 2018-08-10 | 870-497 | 0–9 XXXall 10 · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | JONESBORO | AR |
| 2016-05-05 | 870-360 | 0–9 XXXwhole prefix which blocks → | T-MOBILE USA, INC. | 6529 | PINE BLUFF | AR |
| 2003-10-06 | 870-882 | none assigned yet which blocks → | T-MOBILE USA, INC. | 6529 | JONESBORO | AR |
| 2003-02-04 | 870-440 | 9XXX which blocks → | T-MOBILE USA, INC. | 6529 | EL DORADO | AR |
| 2003-02-04 | 870-441 | none assigned yet which blocks → | T-MOBILE USA, INC. | 6529 | PINE BLUFF | AR |
| 2002-12-23 | 870-390 | 0XXX1XXX3XXX4XXX5XXX7XXX8XXX · 6 holders which blocks → | T-MOBILE USA, INC. | 6529 | CAMDEN | AR |
| 2002-11-12 | 870-868 | 9XXX which blocks → | T-MOBILE USA, INC. | 6529 | ARKADLPHIA | AR |
| 2002-11-07 | 870-292 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | HOPE | AR |
| 2002-03-13 | 870-627 | 0–9 XXXall 10 · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | JONESBORO | AR |
| 2001-05-08 | 870-495 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → | T-MOBILE USA, INC. | 6529 | NEWPORT | AR |
| 2001-01-23 | 870-562 | 2XXX7XXX · 2 holders which blocks → | T-MOBILE USA, INC. | 6529 | MAGNOLIA | AR |
| — | 870-413 | 3XXX4XXX5XXX7XXX8XXX which blocks → | T-MOBILE USA, INC. | 6529 | PINE BLUFF | AR |
| — | 870-519 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → | T-MOBILE USA, INC. | 6529 | FORREST CY | AR |
| — | 870-665 | 0XXX3XXX4XXX5XXX7XXX which blocks → | T-MOBILE USA, INC. | 6529 | EL DORADO | AR |
| — | 870-791 | none assigned yet which blocks → | T-MOBILE USA, INC. | 6529 | CAMDEN | AR |
| — | 870-806 | 0–9 XXXall 10 · 7 holders which blocks → | T-MOBILE USA, INC. | 6529 | BATESVILLE | AR |
| — | 870-824 | 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → | T-MOBILE USA, INC. | 6529 | BLYTHEVL | AR |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.