FAQ Q198: I'd like to keep clients' credit card numbers on file instead of taking an online payment. Is this possible?
Yes, you can do this. Please note that if you decide to use this feature the credit card numbers (encoded) will be saved on YOUR server and you take full responsability for the security of the entire process. This is why you should be able to use SSL on your site (HTTPS protocol) for secure data entry / retrieval. Please see this page
for step-by-step set up instructions.