We can only investigate unauthorised work to protected trees. Protected trees include those in a conservation area or protected by a tree preservation order. Before submitting your complaint, please check whether the tree is protected using mymaps. When you follow the link, select the ‘my maps’ tab, then select 'planning' from the map categories on the left hand side of the screen.
If you still consider the matter you are raising to be a breach of planning control, you can make a complaint.