NPA-NXX - 309-639

This is the 309-639 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. 309
3. 309-639

The 309-639 subcode mainly covers Williamsfield in Knox 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 Mid-century Telephone Cooperative. 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 52919 comments across our systems for the 309-639 subcode.