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 |
|---|---|---|---|---|---|---|
| 2009-10-16 | 313-312 | 0–9 XXXall 10 · 3 holders which blocks → | PAETEC ITEL, LLC | 829J | DETROITZN3 | MI |
| 2009-04-16 | 313-444 | 0–9 XXXall 10 · 2 holders which blocks → | PAETEC ITEL, LLC | 829J | DETROITZN2 | MI |
| 2009-04-14 | 313-288 | 0–9 XXXall 10 · 4 holders which blocks → | PAETEC ITEL, LLC | 829J | DETROITZN4 | MI |
| 2007-07-13 | 313-458 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | PAETEC ITEL, LLC | 829J | DETROITZN2 | MI |
| — | 313-242 | 6XXX7XXX · 2 holders which blocks → | PAETEC ITEL, LLC | 829J | DETROITZN5 | MI |
| — | 313-243 | 2XXX4XXX6XXX · 2 holders which blocks → | PAETEC ITEL, LLC | 829J | DETROITZN4 | MI |
| — | 313-305 | 2XXX3XXX4XXX7XXX · 2 holders which blocks → | PAETEC ITEL, LLC | 829J | DETROITZN3 | MI |
| — | 313-308 | 4XXX5XXX6XXX7XXX · 2 holders which blocks → | PAETEC ITEL, LLC | 829J | DETROITZN2 | MI |
| — | 313-309 | 8XXX which blocks → | PAETEC ITEL, LLC | 829J | DETROITZN1 | MI |
| — | 313-357 | not yet reported which blocks → | PAETEC ITEL, LLC | 829J | DETROITZN6 | MI |
| — | 313-362 | 4XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | PAETEC ITEL, LLC | 829J | DETROITZN5 | MI |
| — | 313-420 | 1XXX3XXX7XXX8XXX9XXX · 3 holders which blocks → | PAETEC ITEL, LLC | 829J | DETROITZN1 | MI |
| — | 313-487 | 0–9 XXXall 10 · 5 holders which blocks → | PAETEC ITEL, LLC | 829J | DETROITZN1 | MI |
| — | 313-637 | 1XXX3XXX4XXX5XXX6XXX8XXX · 2 holders which blocks → | PAETEC ITEL, LLC | 829J | DETROITZN6 | MI |
| — | 313-827 | none assigned yet which blocks → | PAETEC ITEL, LLC | 829J | DETROITZN6 | MI |
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.