NPA-NXX - 657-378

This is the 657-378 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. 657
3. 657-378

The 657-378 subcode mainly covers Fullerton in Orange county. But other numbers maybe included as well.

We have a database of information derived from the public phone records of California state. Many of the numbers in this subcode are Regular Landline registered to Peerless Network. We hear they employ a large number of people in the California office.
Recently there have been an increase in reported calls, we've had over 3010232 comments across our systems for the 657-378 subcode.