This question was answered on our Cruise IQ show on August 17, 2017.
Firstly, other than the casino, you will not be using cash onboard your cruise, so don’t bring wads of bills. Have enough cash on hand if you want to extend an additional gratuity onboard and for buying souvenirs in any ports your visit. While most of the items you’ll need during your cruise are included, you may want to purchase from the duty-free shops onboard or book a shore excursion, specialty dining, spa or any number of other extras. You will be required to provide a form of payment at check-in to change any purchases or services. It is strongly recommended to use a credit card to settle your onboard purchases. If you use a debit-card, the cruise line will place a minimum hold on the card and in cases where you don’t use the full amount, it can take up to two weeks after your cruise to have the funds released. Using cash as your form of payment will require you to provide the cruise line with at least two to three hundred dollars. Once this money is used up, you’ll need to add funds to keep your account open.