I moved DS mid year 5. We had moved house earlier that year, but I kept him at his old school to minimise disruption to him for a few months.
I just contacted the school i wanted him to go to, and went to speak to the head. she confirmed that he could attend. I then wrote tothe head at the schoolhe was currently attending and informed them that he was changing. I didn't see any forms.?
this was 4 years ago, so maybe procedures have changed since then.