The final count and the balance
A party's count can change until it locks, a few days before the party. At the lock, the count is final and the balance is charged to the card the parent booked with.
Before the lock
The parent changes the number of children, or their add-ons, from their party's page, and sees what the bill comes to before saving. A week before, they're reminded how many are coming and when the count locks.

From the party's page, More has the same for you: Change the count, up or down until the lock and only up after it; Add-ons; Change the host; Move the party; and Cancel the party.

At the lock
If more guests said they're coming than were booked, the count goes up to match, and the bill with it. Then the balance is charged to the parent's card, and you're told if any is still owed.
Moving and cancelling
Parents can move their party once, free, until a week before (the package's Moved free days); you can move it whenever you need. A host can be swapped for anyone free then.

Cancelling before the lock keeps the deposit; a parent sees that before they confirm. When it's you who can't host it, choose We can't host it, and everything paid goes back.
