By default, only the school plan will be retained and upgraded to Premium and you will be able to toggle between Premium and School plan in the KooBits portal.
Only CPs from your child's school account will be retained (to prevent overlap of CPs from the daily limit of 26 CPs). KoKoCredits can be merged for both accounts.
Activity history (such as under Mission & Assignment) is only retained from school account.
Note: You have the option to request for reversed arrangement via this form.