You can put a hold on the kids cards so they can't charge but.... we found out that they can still use them to acess the internet in the cafe. 10 year old had a field day one afternoon. luckily we found him before it got too out of hand. You can purchase drink stamps at the start and have them put on their cards if you want. depends on how old kids are. 10 year old earned his money for sodas and extras so we just applied it to the seas pass as a credit and that worked. didn't allow him to charge in the shops on board.