3 Answers

Hire a surveyor to determine the lot boundary line.  From there you can determine the location of your fence.  If it's YOUR fence, build it 2 inches inside your boundary.  Otherwise, you must have it in writing with your neighbor, and have it recorded.  It'll transfer with the land.

Lastly, you may need a permit for the fence.  Watch for height limitation too.

You can not force your neighbor to share in the cost of your fence. In my state the fence has to be erected one foot away from the boundary line and can not be higher than 6 feet. I can not put a fence in my front yard. You better check with your zoning dept for where you can place the fence and how tall it can be.

Taking the other guys side for a moment: You wish to build a fence so what,build it wholely on your land and leave me alone.Just because you decide to do something how can you figure that you are entitled to get in my pocket to get it done. Lifes tough at the moment and I dont need to be paying for something you want. This sucks I dont have hundreds of dollars to pay for your project. Just saying there are two sides to everything and its only fair to see both sides .