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 |
|---|---|---|---|---|---|---|
| 2006-04-17 | 228-376 | 0–9 XXXwhole prefix which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MS | 5178 | BILOXI | MS |
| 2002-07-16 | 228-220 | 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MS | 5178 | BAYSTLOUIS | MS |
| 2002-07-16 | 228-222 | 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MS | 5178 | PASSCHRSTN | MS |
| 2002-04-29 | 228-284 | 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MS | 5178 | GULFPORT | MS |
| 2002-04-29 | 228-447 | 0XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MS | 5178 | OCEAN SPG | MS |
| 2002-04-29 | 228-471 | 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MS | 5178 | PASCAGOULA | MS |
| 2002-03-04 | 228-591 | 0–9 XXXall 10 · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MS | 5178 | VANCLEAVE | MS |
| — | 228-205 | 2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MS | 5178 | PASCAGOULA | MS |
| — | 228-206 | 7XXX8XXX · 2 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MS | 5178 | GULFPORT | MS |
| — | 228-207 | not yet reported which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MS | 5178 | BILOXI | MS |
| — | 228-275 | 1XXX which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MS | 5178 | BILOXI | MS |
| — | 228-314 | 0XXX3XXX4XXX · 2 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MS | 5178 | GULFPORT | MS |
| — | 228-372 | 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MS | 5178 | PASCAGOULA | MS |
| — | 228-377 | none assigned yet which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MS | 5178 | BILOXI | MS |
| — | 228-395 | 7XXX8XXX which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MS | 5178 | BAYSTLOUIS | MS |
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.