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 |
|---|---|---|---|---|---|---|
| 2017-04-17 | 413-299 | 0–9 XXXall 10 · 6 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MA | 7103 | HATFIELD | MA |
| 2001-07-10 | 413-308 | 1XXX3XXX5XXX6XXX7XXX9XXX · 6 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MA | 7103 | LUDLOW | MA |
| — | 413-223 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MA | 7103 | GREENFIELD | MA |
| — | 413-224 | 0XXX1XXX2XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MA | 7103 | ELONGMEDOW | MA |
| — | 413-241 | 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MA | 7103 | SPRINGFLD | MA |
| — | 413-242 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MA | 7103 | PITTSFIELD | MA |
| — | 413-271 | 0XXX1XXX2XXX4XXX5XXX6XXX7XXX · 4 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MA | 7103 | SPRINGFLD | MA |
| — | 413-272 | 3XXX5XXX8XXX9XXX · 2 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MA | 7103 | SPRINGFLD | MA |
| — | 413-279 | 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX · 6 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MA | 7103 | WILBRAHAM | MA |
| — | 413-324 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MA | 7103 | PALMER | MA |
| — | 413-362 | 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MA | 7103 | AMHERST | MA |
| — | 413-377 | 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MA | 7103 | CHICOPEE | MA |
| — | 413-887 | 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 3 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MA | 7103 | HOLYOKE | MA |
| — | 413-923 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MA | 7103 | NORTHAMPTN | MA |
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.