NPA-NXX - 618-666

This is the 618-666 subcode (NPA-NXX) prefix page. Follow a prefix to find the number you are looking for. We divide our pages up to make them more user friendly to navigate!

1. Area Codes
2. 618
3. 618-666

The 618-666 subcode mainly covers Collinsville in Madison county. But other numbers maybe included as well.

We have a database of information derived from the public phone records of Illinois state. Many of the numbers in this subcode are Regular Landline registered to Neutral Tandem. We hear they employ a large number of people in the Illinois office.
Recently there have been an increase in reported calls, we've had over 269282 comments across our systems for the 618-666 subcode.