Disney gets an authorization for a set amount on your credit card. It is different at each level of resort. For example, at a value resort the credit limit might be $500, but at a moderate $1000. (Not sure the exact amts, but do know they vary as I have been to both Pop and CBR and had different amts and this was the explanation the CM gave us.) Each time you charge the limit amt, then disney actually charges your credit card for that amt. They will then authorize the amt again to allow you to continue charging. You won't be able to charge more than the amt of credit you have on your card. HTH