You will need to enter your credit card information when you reserve a listing. Your card will not be charged until the host officially approves your reservation.
After you start your rental period, you will be charged monthly on the day of the month you started. For example, if you start your reservation on December 25, you will pay the first day, and then monthly on the 25th of every month.
If you need to change the credit card on file at anytime, you can go to Payment Methods on your profile and fill in the new payment information.