Techniques are disclosed for using business events as triggers to drive payment processing for electronic commerce. As the business logic of a merchant's e-commerce software application reaches various stages that impact payment considerations, it issues a corresponding event notification. According to preferred embodiments, these event notifications are processed by a policy engine, which locates policy information or rules previously configured for that event. Actions are then carried out, based on the configured policy. The merchant e-commerce application is therefore shielded from the details of the underlying payment processing. New payment types can be provided, and existing payment types can be modified if necessary, by adding/modifying policies; the merchant's e-commerce application does not need to change. This event-driven model allows application developers to focus on creating software for the merchant's key business requirements, and makes it easier to maintain the software.