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 |
|---|---|---|---|---|---|---|
| 2022-02-14 | 253-354 | 0–9 XXXall 10 · 4 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | TACOMA | WA |
| 2021-09-28 | 253-374 | 0–9 XXXall 10 · 3 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | AUBURN | WA |
| 2018-04-06 | 253-525 | 0–9 XXXall 10 · 5 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | GIG HARBOR | WA |
| 2015-05-18 | 253-844 | 0–9 XXXall 10 · 4 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | TACOMA | WA |
| 2013-10-24 | 253-371 | not yet reported which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | TACOMA | WA |
| 2002-09-12 | 253-880 | 1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | AUBURN | WA |
| 2002-09-12 | 253-881 | 1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - WA | 7274 | PUYALLUP | WA |
| 2002-09-12 | 253-882 | 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | TACOMA | WA |
| 2002-09-12 | 253-883 | 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - WA | 7274 | TACOMAWVLY | WA |
| 2001-07-30 | 253-251 | 4XXX5XXX9XXX · 3 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - WA | 7274 | PUYALLUP | WA |
| 2001-03-29 | 253-214 | 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - WA | 7274 | DES MOINES | WA |
| 2001-03-29 | 253-234 | 1XXX2XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | KENT | WA |
| — | 253-398 | 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - WA | 7274 | KENT | WA |
| — | 253-414 | 2XXX3XXX4XXX5XXX7XXX8XXX · 2 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | TACOMA | WA |
| — | 253-439 | 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - WA | 7274 | TACOMA | WA |
| — | 253-479 | not yet reported which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | KENT | WA |
| — | 253-518 | 3XXX4XXX5XXX8XXX · 2 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | KENT | WA |
| — | 253-561 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | AUBURN | WA |
| — | 253-733 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 3 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - WA | 7274 | DES MOINES | 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.