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 |
|---|---|---|---|---|---|---|
| 2014-06-19 | 813-452 | 0–9 XXXall 10 · 3 holders which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | TAMPACEN | FL |
| 2013-06-12 | 813-456 | 0–9 XXXwhole prefix which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | TAMPACEN | FL |
| 2011-07-19 | 813-529 | 0–9 XXXwhole prefix which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | TAMPACEN | FL |
| 2006-05-12 | 813-826 | 0–9 XXXwhole prefix which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | TAMPACEN | FL |
| 2002-01-03 | 813-433 | 0XXX1XXX3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | TAMPAWST | FL |
| 2002-01-03 | 813-434 | 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | TAMPASTH | FL |
| 2002-01-03 | 813-435 | 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | TAMPANTH | FL |
| 2002-01-03 | 813-436 | 0XXX1XXX3XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | TAMPAEST | FL |
| 2002-01-03 | 813-720 | 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | PLANT CITY | FL |
| — | 813-316 | 3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | TAMPA | FL |
| — | 813-317 | 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | TAMPA | FL |
| — | 813-377 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | ZEPHYRHILS | FL |
| — | 813-386 | not yet reported which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | TAMPACEN | FL |
| — | 813-387 | not yet reported which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | TAMPACEN | FL |
| — | 813-676 | not yet reported which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | TAMPACEN | FL |
| — | 813-747 | not yet reported which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | PLANT CITY | FL |
| — | 813-762 | not yet reported which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | ZEPHYRHILS | FL |
| — | 813-827 | not yet reported which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | TAMPACEN | FL |
| — | 813-828 | not yet reported which blocks → | LEVEL 3 TELECOM OF FLORIDA, LP - FL | 7635 | TAMPACEN | FL |
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.