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 |
|---|---|---|---|---|---|---|
| 2011-06-01 | 210-631 | 0–9 XXXwhole prefix which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| 2010-08-24 | 210-539 | 0–9 XXXwhole prefix which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| 2010-01-28 | 210-466 | 0–9 XXXwhole prefix which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| 2007-09-18 | 210-808 | 0–9 XXXwhole prefix which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| 2007-01-24 | 210-312 | 0–9 XXXwhole prefix which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| 2004-12-13 | 210-855 | 0–9 XXXwhole prefix which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| 2004-06-24 | 210-237 | 0–9 XXXall 10 · 3 holders which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| 2003-11-06 | 210-221 | not yet reported which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| 2003-11-06 | 210-295 | not yet reported which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| — | 210-249 | 1XXX6XXX8XXX · 2 holders which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| — | 210-268 | 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| — | 210-292 | not yet reported which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| — | 210-395 | 0–9 XXXall 10 · 2 holders which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| — | 210-477 | not yet reported which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| — | 210-546 | not yet reported which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| — | 210-572 | not yet reported which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| — | 210-581 | not yet reported which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| — | 210-582 | not yet reported which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| — | 210-671 | not yet reported which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| — | 210-916 | not yet reported which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
| — | 210-925 | not yet reported which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 8434 | SANANTONIO | TX |
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.