Abstract: Described is a technology by which a payment abstraction layer enables application program developers to setup and/or enhance application programs to accept several payment tenders (e.g., including credit, debit, check and so forth) without requiring the application programs to implement the particular details of each payment solution provider. The payment abstraction layer provides enumeration methods and payment-related methods that are called by an application program to process payment-related input data, and instantiates payment objects to communicate with payment service providers. The payment abstraction layer may further include a hierarchy of tender (payment instrument) classes in which one class encapsulates data for different types of tenders. Some payment-related methods may be independent of any tender type, whereby an application program only need call an appropriate method with tender input data regardless of its source.