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 |
|---|---|---|---|---|---|---|
| 2024-11-07 | 857-822 | 2XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | ONVOY SPECTRUM, LLC | 624H | SOMERVILLE | MA |
| 2024-11-07 | 857-833 | 3XXX7XXX8XXX9XXX · 2 holders which blocks → | ONVOY SPECTRUM, LLC | 624H | WINTHROP | MA |
| 2024-11-07 | 857-857 | 0–9 XXXall 10 · 2 holders which blocks → | ONVOY SPECTRUM, LLC | 624H | NEWTON | MA |
| 2021-03-17 | 857-847 | 0–9 XXXall 10 · 3 holders which blocks → | ONVOY SPECTRUM, LLC | 624H | DORCHESTER | MA |
| 2021-03-17 | 857-867 | 0–9 XXXall 10 · 3 holders which blocks → | ONVOY SPECTRUM, LLC | 624H | BROOKLINE | MA |
| 2020-12-18 | 857-887 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → | ONVOY SPECTRUM, LLC | 624H | JAMAICA PL | MA |
| 2017-09-22 | 857-298 | 0–9 XXXall 10 · 2 holders which blocks → | ONVOY SPECTRUM, LLC | 624H | CAMBRIDGE | MA |
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.