Working with EFT

I have an application that tracks students. I would like to be able to integrate it with banking functions such as Electronic Funds Transfer (EFT). Basically, when money is paid to the students account through credit card or EFT the information is sent to the application and the student's status is updated in the application. I would suspect that an additional software package is required to make the link between my application and the bank. If anyone has any knowledge in this area or can send me a link to a resource on this topic I'd appreciate it.