Think of the Sail-n-Sign as your ATM card. You can only take out of your account what you put in. The cruise line also takes your credit card number just in case at the end of the cruise you still have a balance due. On your t.v. you can check you balance, or you can go to the Purser's desk and talk to them. I always put whatever I am going to spend that day on my card the same day. That way, if I loose the card and someone else uses it, they won't get much. Expect the tips for the cruise to be placed on the Sail-n-Sign card when you board the ship and it is usually $9.50 per person per day.