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 |
|---|---|---|---|---|---|---|
| 2025-08-12 | 534-243 | 0XXX1XXX2XXX3XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | ONVOY, LLC - WI | 225C | HUDSON | WI |
| 2025-08-12 | 534-244 | 0–9 XXXall 10 · 3 holders which blocks → | ONVOY, LLC - WI | 225C | RHINELANDR | WI |
| 2024-03-21 | 534-231 | 0XXX1XXX2XXX8XXX9XXX which blocks → | ONVOY, LLC - WI | 225C | STEVENS PT | WI |
| 2024-03-21 | 534-232 | 0–9 XXXall 10 · 2 holders which blocks → | ONVOY, LLC - WI | 225C | WAUSAU | WI |
| 2024-02-19 | 534-534 | 5XXX which blocks → | ONVOY, LLC - WI | 225C | WEBSTER | WI |
| 2023-09-05 | 534-224 | 2XXX4XXX · 2 holders which blocks → | ONVOY, LLC - WI | 225C | BIRCHWOOD | WI |
| 2023-07-19 | 534-217 | 0XXX2XXX · 2 holders which blocks → | ONVOY, LLC - WI | 225C | MERRILLAN | WI |
| 2021-12-17 | 534-277 | 0–9 XXXall 10 · 4 holders which blocks → | ONVOY, LLC - WI | 225C | STEVENS PT | WI |
| 2021-06-28 | 534-203 | 0–9 XXXall 10 · 3 holders which blocks → | ONVOY, LLC - WI | 225C | RIVERFALLS | WI |
| 2021-05-26 | 534-535 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks → | ONVOY, LLC - WI | 225C | JUNCTIONCY | WI |
| 2018-12-05 | 534-344 | 0–9 XXXwhole prefix which blocks → | ONVOY, LLC - WI | 225C | WHITEHALL | WI |
| 2018-12-05 | 534-544 | 0–9 XXXall 10 · 5 holders which blocks → | ONVOY, LLC - WI | 225C | HUDSON | WI |
| 2018-11-19 | 534-444 | 0–9 XXXall 10 · 2 holders which blocks → | ONVOY, LLC - WI | 225C | EAU CLAIRE | WI |
| 2018-09-25 | 534-400 | 0–9 XXXall 10 · 3 holders which blocks → | ONVOY, LLC - WI | 225C | WAUPACA | WI |
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.