Just an FYI post as I've realised it isn't widely known/theres alot of misinformation out there.
If your child is born after 1st April they are classified as summerborn and can therefore start primary school into reception class at age 5. They will never have to skip a year and will stay with their adopted cohort throughout primary and secondary school. There doesn't need to be any reason to defer other than being summerborn.
It has become so common for parents to do this especially if their child is born in June, July or August. Who wouldn't want their child to be the oldest in the class rather than the youngest!?
For more info join the fb group:
'Flexible school admission for summer borns'