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 |
|---|---|---|---|---|---|---|
| 2021-09-21 | 530-857 | 1XXX8XXX9XXX · 2 holders which blocks → | IP HORIZON LLC | 515J | CHICO | CA |
| — | 530-204 | 0XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | IP HORIZON LLC | 515J | DAVIS | CA |
| — | 530-207 | 0XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | IP HORIZON LLC | 515J | WOODLAND | CA |
| — | 530-213 | 0XXX3XXX5XXX6XXX7XXX9XXX · 5 holders which blocks → | IP HORIZON LLC | 515J | NTAH BCWY | CA |
| — | 530-214 | 0XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | IP HORIZON LLC | 515J | TRUCKEE | CA |
| — | 530-217 | 3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | IP HORIZON LLC | 515J | AUBN MAIN | CA |
| — | 530-331 | 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | IP HORIZON LLC | 515J | YREKA | CA |
| — | 530-334 | 0–9 XXXall 10 · 6 holders which blocks → | IP HORIZON LLC | 515J | GEORGETOWN | CA |
| — | 530-361 | 0XXX3XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → | IP HORIZON LLC | 515J | WILLOWS | CA |
| — | 530-413 | 0XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | IP HORIZON LLC | 515J | PARADISE | CA |
| — | 530-501 | 0XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | IP HORIZON LLC | 515J | WILLIAMS | CA |
| — | 530-502 | 5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | IP HORIZON LLC | 515J | PRINCETON | CA |
| — | 530-503 | 0XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | IP HORIZON LLC | 515J | PLVL SOUTH | CA |
| — | 530-535 | 0XXX3XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → | IP HORIZON LLC | 515J | ALLEGHANY | CA |
| — | 530-540 | not yet reported which blocks → | IP HORIZON LLC | 515J | CHICO | CA |
| — | 530-568 | 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | IP HORIZON LLC | 515J | MT SHASTA | CA |
| — | 530-646 | 3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | IP HORIZON LLC | 515J | REDDING | CA |
| — | 530-737 | 3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | IP HORIZON LLC | 515J | RED BLUFF | CA |
| — | 530-773 | 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | IP HORIZON LLC | 515J | LOYALTON | CA |
| — | 530-776 | 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | IP HORIZON LLC | 515J | ANDERSON | CA |
| — | 530-793 | 3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → | IP HORIZON LLC | 515J | PASKENTA | CA |
| — | 530-861 | 0XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → | IP HORIZON LLC | 515J | VINA | CA |
| — | 530-948 | 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | IP HORIZON LLC | 515J | MERIDIAN | CA |
| — | 530-962 | 0XXX3XXX4XXX5XXX6XXX8XXX9XXX · 7 holders which blocks → | IP HORIZON LLC | 515J | SHASTALAKE | CA |
| — | 530-988 | 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 8 holders which blocks → | IP HORIZON LLC | 515J | ORLAND | CA |
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.