How can I set or change my preferred payment method?

How can I set or change my preferred payment method? You can switch between available payment methods any time, during the sign-up process or under 'Billing information' in the 'Account Info' section, once logged in. Please note that a payment-method change performed after the 15th will be processed on the following month (i.e. a payment method change on the 18th will impact only next month payment).