NumberResearchRecent prefix assignments
1 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026
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 |
|---|---|---|---|---|---|---|
| — | 858-911 | not yet reported which blocks → | MULTIPLE OCN LISTING | MULT | XXXXXXXXXX | CA |
| — | 858-914 | 0–9 XXXall 10 · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | RNCHOSANFE | CA |
| — | 858-922 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | LA JOLLA | CA |
| — | 858-923 | 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | MATRIX TELECOM, LLC. S/I/I TNCI - CA | 7379 | RNCHOSANFE | CA |
| — | 858-924 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → | PACIFIC BELL | 9740 | RNCHOBRNDO | CA |
| — | 858-925 | 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | DEL MAR | CA |
| — | 858-926 | 0XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | LA JOLLA | CA |
| — | 858-927 | 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | ONVOY, LLC - CA | 649C | RNCHOBRNDO | CA |
| — | 858-935 | 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA | 7240 | SNDG MRMS | CA |
| — | 858-939 | 0XXX1XXX9XXX · 3 holders which blocks → | PACIFIC BELL | 9740 | SNDG LVTA | CA |
| — | 858-942 | not yet reported which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 7147 | RNCHOBRNDO | CA |
| — | 858-943 | 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | LEVEL 3 TELECOM OF CALIFORNIA, LP - CA | 7718 | RNCHOBRNDO | CA |
| — | 858-945 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 6006 | LA JOLLA | CA |
| — | 858-946 | 3XXX4XXX5XXX8XXX9XXX · 4 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA | 7240 | RNCHOBRNDO | CA |
| — | 858-947 | 3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → | MATRIX TELECOM, LLC. S/I/I TNCI - CA | 7379 | DEL MAR | CA |
| — | 858-950 | not yet reported which blocks → | CA | |||
| — | 858-951 | 1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - CA | 8826 | RNCHOSANFE | CA |
| — | 858-956 | 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | MATRIX TELECOM, LLC. S/I/I TNCI - CA | 7379 | POWAY | CA |
| — | 858-958 | not yet reported which blocks → | CA | |||
| — | 858-959 | not yet reported which blocks → | CA | |||
| — | 858-964 | 8XXX which blocks → | PAETEC ITEL, LLC | 829J | LA JOLLA | CA |
| — | 858-966 | 0XXX3XXX9XXX · 2 holders which blocks → | PACIFIC BELL | 9740 | SNDG LVTA | CA |
| — | 858-967 | none assigned yet which blocks → | T-MOBILE USA, INC. | 6529 | LA JOLLA | CA |
| — | 858-974 | not yet reported which blocks → | PACIFIC BELL | 9740 | SNDG LVTA | CA |
| — | 858-976 | not yet reported which blocks → | CA | |||
| — | 858-987 | 0–9 XXXall 10 · 7 holders which blocks → | ONVOY, LLC - CA | 649C | SNDG LVTA | CA |
| — | 858-999 | 0–9 XXXall 10 · 6 holders which blocks → | ONVOY, LLC - CA | 649C | LA JOLLA | CA |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.