Yes, you have to use CC if you book on line. Also, if you plan to send a check, just ask for the payment address when you call to make your reservation and tell them you are planning to pay by check. That way, you won't have to wait for the confirmation letter. Also, I would call and see if it got there by the deposit deadline. If not, they can usually extend the date by a few days for you. We've done this before. They're usually very accommodating.