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 |
|---|---|---|---|---|---|---|
| — | 972-265 | 7XXX9XXX · 2 holders which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 7516 | PLANO | TX |
| — | 972-350 | 6XXX7XXX which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 7516 | LEWISVILLE | TX |
| — | 972-421 | 8XXX which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 7516 | DALLAS | TX |
| — | 972-426 | 1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 7516 | DLFTWTARPT | TX |
| — | 972-428 | 2XXX3XXX4XXX7XXX8XXX9XXX · 4 holders which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 7516 | CARROLLTON | TX |
| — | 972-464 | 1XXX2XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 7516 | FRISCO | TX |
| — | 972-521 | 1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 7516 | ALLEN | TX |
| — | 972-590 | 6XXX8XXX which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 7516 | DALLAS | TX |
| — | 972-616 | 3XXX4XXX which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 7516 | DALLAS | TX |
| — | 972-637 | 1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 7516 | CEDAR HILL | TX |
| — | 972-748 | 1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 7516 | DE SOTO | TX |
| — | 972-786 | 1XXX2XXX3XXX4XXX5XXX6XXX which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 7516 | IRVING | TX |
| — | 972-854 | 1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 7516 | GRANDPRARI | TX |
| — | 972-894 | 3XXX which blocks → | LEVEL 3 OF TELECOM OF TEXAS, LLC - TX | 7516 | IRVING | 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.