NumberResearchRecent prefix assignments
0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/21/2026
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 |
|---|---|---|---|---|---|---|
| — | 928-332 | 1XXX3XXX5XXX · 3 holders which blocks → | CITIZENS TELECOM CO OF WHITE MOUNTAINS INC. | 4426 | WHITERIVER | AZ |
| — | 928-333 | not yet reported which blocks → | CITIZENS TELECOM CO OF WHITE MOUNTAINS INC. | 4426 | SPRINGERVL | AZ |
| — | 928-334 | none assigned yet which blocks → | CITIZENS TELECOM CO OF WHITE MOUNTAINS INC. | 4426 | WHITERIVER | AZ |
| — | 928-335 | none assigned yet which blocks → | CITIZENS TELECOM CO OF WHITE MOUNTAINS INC. | 4426 | WHITERIVER | AZ |
| — | 928-337 | 1XXX8XXX · 2 holders which blocks → | CITIZENS TELECOM CO OF WHITE MOUNTAINS INC. | 4426 | ST JOHNS | AZ |
| — | 928-338 | 6XXX7XXX9XXX · 2 holders which blocks → | CITIZENS TELECOM CO OF WHITE MOUNTAINS INC. | 4426 | WHITERIVER | AZ |
| — | 928-339 | 2XXX3XXX5XXX7XXX8XXX · 4 holders which blocks → | CITIZENS TELECOM CO OF WHITE MOUNTAINS INC. | 4426 | ALPINE | AZ |
| — | 928-367 | not yet reported which blocks → | CITIZENS TELECOM CO OF WHITE MOUNTAINS INC. | 4426 | PINETOP | AZ |
| — | 928-368 | 3XXX7XXX9XXX · 2 holders which blocks → | CITIZENS TELECOM CO OF WHITE MOUNTAINS INC. | 4426 | PINETOP | AZ |
| — | 928-369 | 6XXX8XXX9XXX · 2 holders which blocks → | CITIZENS TELECOM CO OF WHITE MOUNTAINS INC. | 4426 | PINETOP | AZ |
| — | 928-524 | none assigned yet which blocks → | CITIZENS TELECOM CO OF WHITE MOUNTAINS INC. | 4426 | HOLBROOK | AZ |
| — | 928-532 | not yet reported which blocks → | CITIZENS TELECOM CO OF WHITE MOUNTAINS INC. | 4426 | SHOW LOW | AZ |
| — | 928-535 | 1XXX2XXX · 2 holders which blocks → | CITIZENS TELECOM CO OF WHITE MOUNTAINS INC. | 4426 | HEBER | AZ |
| — | 928-536 | not yet reported which blocks → | CITIZENS TELECOM CO OF WHITE MOUNTAINS INC. | 4426 | SNOWFLAKE | AZ |
| — | 928-537 | not yet reported which blocks → | CITIZENS TELECOM CO OF WHITE MOUNTAINS INC. | 4426 | SHOW LOW | AZ |
| — | 928-735 | 1XXX3XXX4XXX6XXX8XXX · 2 holders which blocks → | CITIZENS TELECOM CO OF WHITE MOUNTAINS INC. | 4426 | GREER | AZ |
| — | 928-739 | none assigned yet which blocks → | CITIZENS TELECOM CO OF WHITE MOUNTAINS INC. | 4426 | SHOW LOW | AZ |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/21/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.