NPA-NXX - 603-666

This is the 603-666 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. 603
3. 603-666

The 603-666 subcode mainly covers Manchester in Hillsborough county. But other numbers maybe included as well.

We have a database of information derived from the public phone records of New Hampshire state. Many of the numbers in this subcode are Regular Landline registered to Fairpoint Communications. We hear they employ a large number of people in the New Hampshire office.
Recently there have been an increase in reported calls, we've had over 400721 comments across our systems for the 603-666 subcode.