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 |
|---|---|---|---|---|---|---|
| 2022-07-13 | 661-649 | 0–9 XXXall 10 · 3 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | ARVIN | CA |
| 2022-06-29 | 661-590 | 0XXX1XXX2XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | WASCO | CA |
| 2022-05-26 | 661-595 | 0–9 XXXall 10 · 4 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | BKFD MAIN | CA |
| 2022-05-26 | 661-687 | 0–9 XXXall 10 · 5 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | BKFD SOUTH | CA |
| 2014-04-25 | 661-493 | 0–9 XXXall 10 · 7 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | BKFD MAIN | CA |
| 2009-05-21 | 661-381 | 0–9 XXXall 10 · 4 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | BKFD SOUTH | CA |
| 2006-12-14 | 661-390 | 0–9 XXXall 10 · 3 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | ARVIN | CA |
| 2005-05-16 | 661-431 | 0–9 XXXall 10 · 4 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | BKFD MAIN | CA |
| 2002-10-11 | 661-377 | 4XXX5XXX6XXX8XXX · 2 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | BKFD MAIN | CA |
| 2002-08-09 | 661-705 | 6XXX which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | SNCA NHCS | CA |
| 2001-03-01 | 661-410 | 2XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | BKFD NORTH | CA |
| 2001-03-01 | 661-716 | not yet reported which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | BKFD MAIN | CA |
| 2001-03-01 | 661-847 | 0XXX3XXX8XXX9XXX · 4 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | BKFD SOUTH | CA |
| — | 661-964 | 0XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | 671J | SNCA NHCS | 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.