Sometimes, you might face a situation when a family member can't make a purchase for some reason. That's where the family organizer should take charge— he or she needs to move a different payment method to the top of the list.
Important: Only a family administrator (aka family organizer) can manage payment methods.
If you are a family administrator, feel free to add multiple payment methods to your own Apple ID.
The family members, however, can use only the first payment method on the list.
Now your family members have an opportunity to buy stuff without disturbing you while you are on holiday or having a great time with friends:)