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 |
|---|---|---|---|---|---|---|
| 2003-02-21 | 810-991 | 0–9 XXXall 10 · 8 holders which blocks → | 123.NET, LLC | 2550 | HARTLAND | MI |
| 2001-12-28 | 810-375 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 8 holders which blocks → | 123.NET, LLC | 2550 | DRYDEN | MI |
| 2001-12-28 | 810-442 | 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | 123.NET, LLC | 2550 | DECKERVL | MI |
| 2001-10-18 | 810-512 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → | 123.NET, LLC | 2550 | ALGONAC | MI |
| — | 810-267 | 0–9 XXXall 10 · 5 holders which blocks → | 123.NET, LLC | 2550 | LAPEER | MI |
| — | 810-315 | 0XXX6XXX9XXX · 3 holders which blocks → | 123.NET, LLC | 2550 | DRYDEN | MI |
| — | 810-371 | 0XXX2XXX3XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → | 123.NET, LLC | 2550 | CAPAC | MI |
| — | 810-390 | 0XXX5XXX · 2 holders which blocks → | 123.NET, LLC | 2550 | FENTON | MI |
| — | 810-426 | 0XXX5XXX · 2 holders which blocks → | 123.NET, LLC | 2550 | MARINECITY | MI |
| — | 810-699 | 0XXX5XXX which blocks → | 123.NET, LLC | 2550 | APPLEGATE | MI |
| — | 810-827 | 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX · 5 holders which blocks → | 123.NET, LLC | 2550 | EMMETT | MI |
| — | 810-901 | 0XXX5XXX which blocks → | 123.NET, LLC | 2550 | SANDUSKY | MI |
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.