Prefix overview
Phone numbers in prefix 303-406
This page covers the 303-406 prefix in the United States. It shows where numbers come from, which carrier is linked to the range, and how this block is structured.
If you are looking for a specific number, you can continue to its dedicated phone page. Otherwise, this page helps you understand the broader number block behind it.
PREFIX
303-406
RATE CENTER
DENVER
CARRIER
LEVEL 3 COMMUNICATIONS, LLC - CO
CO
Prefix range
The prefix 303-406 includes numbers from 3034060000 to 3034069999.
This range is associated with the DENVER rate center and was originally assigned to LEVEL 3 COMMUNICATIONS, LLC - CO.
Numbers in this prefix
20 numbers