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 |
|---|---|---|---|---|---|---|
| 2006-06-27 | 519-946 | not yet reported which blocks → | Zayo Canada Inc. | 8304 | Windsor | — |
| 2004-07-30 | 519-286 | not yet reported which blocks → | Zayo Canada Inc. | 8304 | London | — |
| 2004-07-30 | 519-340 | not yet reported which blocks → | Zayo Canada Inc. | 8304 | Kitchener-Waterloo | — |
| 2004-07-30 | 519-947 | not yet reported which blocks → | Zayo Canada Inc. | 8304 | Preston | — |
| 2004-07-29 | 519-231 | not yet reported which blocks → | Zayo Canada Inc. | 8304 | Galt | — |
| 2004-07-29 | 519-248 | not yet reported which blocks → | Zayo Canada Inc. | 8304 | Hespeler | — |
| 2001-10-23 | 519-964 | not yet reported which blocks → | Zayo Canada Inc. | 8304 | London | — |
| 2000-07-17 | 519-201 | not yet reported which blocks → | Zayo Canada Inc. | 8304 | Preston | — |
| 2000-07-17 | 519-224 | not yet reported which blocks → | Zayo Canada Inc. | 8304 | Hespeler | — |
| 2000-07-17 | 519-629 | not yet reported which blocks → | Zayo Canada Inc. | 8304 | Galt | — |
| — | 519-772 | not yet reported which blocks → | Zayo Canada Inc. | 8304 | Kitchener-Waterloo | — |
| — | 519-963 | not yet reported which blocks → | Zayo Canada Inc. | 8304 | London | — |
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.