Add to previous post, charges are deducted in this order: non-refundable onboard credit, refundable onboard credit (like gift cards if applied to room), then designated payment (credit card on file, then cash).
The limit before they cut off charging privileges is $400 or $500.
I like to avoid visiting Guest Services (saving vacation time) - and I like to use a Disney Gift Card. So I make a gift to myself through the
DCL website (Maybe app works for this, too). It’s under Already Booked > Onboard Gifts > Onboard Credit (found through = at top left corner).
That puts the money in my account. You can designate it a specific guest.
If it doesn’t get used, any remaining funds go back to that same card (so keep that info).