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 |
|---|---|---|---|---|---|---|
| 2008-01-14 | 707-560 | 0–9 XXXall 10 · 8 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | CLERLAOAKS | CA |
| 2001-12-27 | 707-302 | 0XXX4XXX5XXX6XXX8XXX9XXX · 3 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | ST HELENA | CA |
| 2001-09-28 | 707-709 | 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | CALISTOGA | CA |
| — | 707-266 | 1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | NAPA | CA |
| — | 707-303 | 0XXX3XXX5XXX6XXX7XXX · 4 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | SANTA ROSA | CA |
| — | 707-583 | 0XXX1XXX3XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | SANTA ROSA | CA |
| — | 707-603 | 0XXX5XXX9XXX · 3 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | NAPA | CA |
| — | 707-674 | 0XXX1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | VALLEJO | CA |
| — | 707-720 | 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | FRFLD-SUIS | CA |
| — | 707-721 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | SONOMA | CA |
| — | 707-752 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 5 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | BENICIA | CA |
| — | 707-790 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | PTLM MAIN | CA |
| — | 707-921 | 0XXX1XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | SANTA ROSA | 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.