Merchant Originated Message Formats

The message format of shopping cart transactions will be formatted using XML or URL encoded XML. The Data Type Definitions (DTDs) of these message formats are included in the Appendices.

There are two types of messages sent by a merchant: Shopping Cart Orders and Cardholder Orders.

Shopping Cart Orders allow the customer to fill a “shopping cart” on the merchant’s site. At checkout time, the merchant site redirects the customer to the acquirer site and passes along a summary of the shopping cart along with the order amount. Once redirected, the customer then supplies card and order fulfillment information using the acquirer’s SSL encrypted web site. With this method, the merchant does not need an SSL encrypted web-site.

In the case of a merchant that chooses the Cardholder Orders option, the locus of control for collecting cardholder information passes to the merchant. The merchant must have an SSL encrypted web-site. The merchant thus gathers the information from the cardholder and controls the customer’s entire shopping experience. The merchant then passes the transaction information along to the acquiring system using a Cardholder Order XML document.