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 |
|---|---|---|---|---|---|---|
| 2023-06-28 | 510-389 | 0–9 XXXall 10 · 2 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | OKLD TRNID | CA |
| 2020-12-22 | 510-971 | 0–9 XXXall 10 · 3 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | OKLD MN-PD | CA |
| 2014-12-01 | 510-942 | 0–9 XXXall 10 · 5 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | RICHMOND | CA |
| — | 510-217 | 8XXX which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | OKLD ALMD | CA |
| — | 510-257 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | FRNK OLIVR | CA |
| — | 510-313 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | HRCUL-RODE | CA |
| — | 510-350 | 1XXX3XXX5XXX6XXX7XXX · 4 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | OKLD MN-PD | CA |
| — | 510-394 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | OKLD TRNID | CA |
| — | 510-395 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | OKLD FRTVL | CA |
| — | 510-449 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | FRNK MAIN | CA |
| — | 510-457 | 0XXX1XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | OKLD MN-PD | CA |
| — | 510-479 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 7 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | OKLD FRTVL | CA |
| — | 510-491 | 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | FRNK GRNLF | CA |
| — | 510-837 | 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | RICHMOND | CA |
| — | 510-879 | 5XXX6XXX7XXX · 2 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | OKLD MN-PD | CA |
| — | 510-896 | 0XXX3XXX5XXX7XXX9XXX · 4 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | FRNK MAIN | CA |
| — | 510-897 | 0XXX3XXX5XXX6XXX7XXX9XXX · 5 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | FRNK OLIVR | CA |
| — | 510-898 | 6XXX8XXX · 2 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | OKLD BKLY | CA |
| — | 510-921 | 0XXX1XXX2XXX4XXX6XXX7XXX8XXX9XXX which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7145 | HAYWARD | 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.