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 |
|---|---|---|---|---|---|---|
| 2020-09-16 | 509-403 | 0–9 XXXall 10 · 4 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - WA | 7274 | QUINCY | WA |
| 2019-11-06 | 509-409 | 0–9 XXXwhole prefix which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - WA | 7274 | QUINCY | WA |
| 2019-11-05 | 509-407 | 0–9 XXXall 10 · 4 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - WA | 7274 | QUINCY | WA |
| 2018-08-22 | 509-827 | 0–9 XXXall 10 · 3 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - WA | 7274 | RICHLAND | WA |
| 2014-07-13 | 509-638 | 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
| 2004-03-25 | 509-481 | 0–9 XXXall 10 · 3 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
| 2003-07-16 | 509-885 | 0–9 XXXall 10 · 4 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - WA | 7274 | WENATCHEE | WA |
| — | 509-232 | 9XXX which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
| — | 509-241 | 3XXX6XXX8XXX9XXX · 4 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
| — | 509-242 | 3XXX5XXX6XXX · 2 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
| — | 509-254 | 0–9 XXXall 10 · 5 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | CLARKSTON | WA |
| — | 509-279 | 1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 3 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
| — | 509-295 | 1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | CLARKSTON | WA |
| — | 509-340 | 5XXX9XXX · 2 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
| — | 509-343 | not yet reported which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
| — | 509-344 | 9XXX which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
| — | 509-434 | 2XXX4XXX6XXX8XXX9XXX · 2 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
| — | 509-444 | not yet reported which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
| — | 509-462 | not yet reported which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
| — | 509-477 | 9XXX which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
| — | 509-688 | 3XXX4XXX5XXX7XXX9XXX which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
| — | 509-755 | not yet reported which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
| — | 509-769 | 1XXX2XXX3XXX4XXX7XXX8XXX9XXX · 6 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | CLARKSTON | WA |
| — | 509-777 | 7XXX which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
| — | 509-847 | 0XXX3XXX4XXX5XXX8XXX9XXX · 3 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
| — | 509-984 | none assigned yet which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SPOKANE | WA |
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.