Prefix overview
Phone numbers in prefix 312-255
This page covers the 312-255 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
312-255
RATE CENTER
CHICGOZN01
CARRIER
ILLINOIS BELL TEL CO
IL
Prefix range
The prefix 312-255 includes numbers from 3122550000 to 3122559999.
This range is associated with the CHICGOZN01 rate center and was originally assigned to ILLINOIS BELL TEL CO.
Numbers in this prefix
20 numbers