Harrow 有 ICC,which confuses the hell out of me. If my child is not planning to go to the school, i wouldn't bother with studying all the complicated structures and names and systems of each school, which at the end of the day, is just about taking more money out of parents on top of the already pricy tuition fee
Some schools offer priority to those holding CORPORATE debenture only. Many priority would not be 'activated' until your child pass the admission assessment. Be cautious.
For Harrow, you may pay annual capital levy instead of debenture.