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 |
|---|---|---|---|---|---|---|
| 2007-05-10 | 615-712 | 0–9 XXXall 10 · 3 holders which blocks → | LEVEL 3 TELECOM OF TENNESSEE, LLC - TN | 7517 | NASHVILLE | TN |
| 2005-11-10 | 615-739 | 0–9 XXXall 10 · 4 holders which blocks → | LEVEL 3 TELECOM OF TENNESSEE, LLC - TN | 7517 | NASHVILLE | TN |
| 2002-06-11 | 615-577 | not yet reported which blocks → | LEVEL 3 TELECOM OF TENNESSEE, LLC - TN | 7517 | NASHVILLE | TN |
| — | 615-558 | 0–9 XXXall 10 · 4 holders which blocks → | LEVEL 3 TELECOM OF TENNESSEE, LLC - TN | 7517 | LAVERGNE | TN |
| — | 615-567 | 3XXX4XXX5XXX6XXX7XXX · 4 holders which blocks → | LEVEL 3 TELECOM OF TENNESSEE, LLC - TN | 7517 | FRANKLIN | TN |
| — | 615-627 | 6XXX7XXX8XXX which blocks → | LEVEL 3 TELECOM OF TENNESSEE, LLC - TN | 7517 | NASHVILLE | TN |
| — | 615-628 | 5XXX6XXX7XXX8XXX · 3 holders which blocks → | LEVEL 3 TELECOM OF TENNESSEE, LLC - TN | 7517 | FRANKLIN | TN |
| — | 615-692 | 1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 TELECOM OF TENNESSEE, LLC - TN | 7517 | MURFREESBO | TN |
| — | 615-760 | 5XXX which blocks → | LEVEL 3 TELECOM OF TENNESSEE, LLC - TN | 7517 | NASHVILLE | TN |
| — | 615-772 | 1XXX3XXX4XXX5XXX6XXX7XXX8XXX which blocks → | LEVEL 3 TELECOM OF TENNESSEE, LLC - TN | 7517 | NASHVILLE | TN |
| — | 615-775 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX which blocks → | LEVEL 3 TELECOM OF TENNESSEE, LLC - TN | 7517 | NASHVILLE | TN |
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.