Tree Surgeon in Bromley › Guide
Who is responsible, and what you can do.
The owner of the land where the trunk grows owns the tree and is responsible for keeping it safe, including branches that overhang a neighbour's garden.
In general you may cut branches back to the boundary line, but you should offer the cuttings back to the owner and you must not cut further than the boundary. Always check for a Tree Preservation Order or conservation area first, because cutting without consent can lead to a fine.
Speaking calmly to your neighbour before doing anything usually solves the problem and may mean you can share the cost of getting a professional in.
A tree surgeon can reduce or lift the crown properly, so the tree stays healthy and the work is done safely.