I think booking online you pay for the whole thing up front (but someone else may be able to confirm that as I'm not 100% sure, we booked over the phone). Over the phone I think is different depending on your country of residence. Being from Australia, we can book over the phone, pay no deposit but give a credit card to secure the booking, then the full payment will be charged to that credit card 30 days out from the arrival date. Not sure exactly how it works for bookings from other countries.