My neighbour's tree overhangs my property. Can I prune the tree?
Yes, you are entitled in law to prune back any overhanging branches to your boundary line but not beyond it. You should not trespass onto your neighbour's property to do the works, unless you have permission. You are obliged by law to offer any parts of the tree removed back to the owner before you dispose of them.
If a tree is protected by a Tree Preservation Order, or is within a Conservation Area, then you must apply to the local planning authority for permission to prune the tree. If you are unsure whether a tree is protected or not, contact your local Arboricultural Officer.
However, I would strongly advise that you speak to the tree owner before carrying out any pruning of the tree, as they may well agree to carry out more appropriate works to the tree. Cutting back to an arbitrary line dictated by a legal boundary does not represent good tree management and for the welfare of the tree should be avoided. It is always better to talk before rather than argue afterwards, not only for you but ultimately for the tree.