Electronic Payment processing continues to be a common theme for many Web based applications and while the process is getting easier with the market maturing, there's still a maze of choices and options in setting up your payment solutions and get them integrated into existing applications. In this article, I'll give a high level overview of the electronic payment processing by looking at the various players involved in the payment processing operation and some suggestions and options you have on getting hooked up with the right provider. I'll talk about how the process works, what it takes to get started and what it's going to cost. Finally I'll take you through an application that integrates payment processing and show a class you can use to integrate a few of the common Gateway services into existing applications.

Once you've picked your merchant provider and gateway – the next step is to integrate the payment processing into your Web Application. In order to do this the first step is to create the basic credit card processing routines that can interface your code with the Gateway of your choice. The focus of the following discussion is describe how to create a somewhat generic credit card processing class hierarchy that can work with various providers, and then describe how to use these classes in a custom Web Store application.