NPA-NXX - 636-544

This is the 636-544 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. 636
3. 636-544

The 636-544 subcode mainly covers O'fallon in St. Charles county. But other numbers maybe included as well.

We have a database of information derived from the public phone records of Missouri state. Many of the numbers in this subcode are Cellular (Dedicated) registered to At&t Mobility. We hear they employ a large number of people in the Missouri office.
Recently there have been an increase in reported calls, we've had over 360485 comments across our systems for the 636-544 subcode.