Do I need a permit for a fence?

No, you do not need a permit for a fence.  BUT.......you want to think about a few things when you are installing your fence.  

You can install a fence right on your property line, however you need to know exactly and for certain where that property line is.  If you can't find the property line markers, the only way to know where the property line is is to have it surveyed.  

You also need to think about how you will be able to maintain that fence without going on your neighbor's property.  If you decide to put the fence off the property line so you can maintain it, you also need to know where that property line is.  Overtime fences can be perceived as property lines and can cause issues down the road.  So for the protection of your valuable property, know where your property lines are.

Please also consider......if you are installing a fence near the front of your parcel, make sure you consider what may happen to that fence when a snow plow comes through.  Please do not block your neighbor's ability to see getting out of their driveway or obstruct any views of the road-traveling public.

Note: Fences over six (6) feet tall may be considered a "grudge fence" by the State of New Hampshire.