• The IPN system
• Sale, refund or chargeback for one-time payments without an initial payment (AKA trial) enabled
• Sale for one-time payments with an initial payment (AKA trial) or sale for a subscription
• Rebill for a subscription, or a follow up after a one-time payment initial payment (trial)
• Refund, failed rebill, or chargeback for a recurring subscription payment, or for a one time payment with a trial
• Cancelation of a recurring payment subscription