The nature of transmissions between the cardholder, the merchant and the acquirer depends on whether the transaction is a Shopping Cart Order or a Cardholder Order. In the latter case, the cardholder is completely insulated from the acquirer. The merchant controls the entire transaction with the cardholder.
Shopping Cart Orders are more complicated. Because the merchant redirects the cardholder to the acquirer for checkout processing, additional issues surface in managing the shopping experience for the cardholder. In particular, after checkout, the cardholder should be redirected to the merchant site. To this end, the merchant can specify the redirection URLs to be used by the acquirer following processing of a transaction. These three URLs include where to send the customer following a successfully captured transaction, an unsuccessfully captured transaction, and an unspecified error (such as the backend host system does not respond within a timeout period).
Should the merchant require more texture in redirections than this, the option exists for the merchant to set a cookie on the cardholder’s browser prior to the redirection to the acquirer payment gateway. Upon redirection back to the merchant site, the merchant can then retrieve this cookie and based on its value, redirect the cardholder to the specific page on the merchant site.