Hello Andrew,
The best time to move the tree is when it is dormant - so November ot
March, when the ground is not waterlogged or frozen. Take as much of
the root with you as you can, to reduce a slow year - which is likely
anyway.

How old is the tree? Do you know what root stock it has been grafted
on to?
The reason for the question is the hight of the tree is maily govened
by soil conditions and rootstock. If the tree has been grafted onto M9
- the tree is only likely to get to 7-8ft
Clifford
Bawtry, Doncaster, South Yorkshire