PCI compliance
This should help you:
"The PCI Security Standards Council (pcisecuritystandards.org) is an open global forum for the ongoing development, enhancement, storage, dissemination and implementation of security standards for account data protection.
The PCI Security Standards Council’s mission is to enhance payment account data security by driving education and awareness of the PCI Security Standards. The organization was founded by American Express, Discover Financial Services, JCB International, MasterCard Worldwide, and Visa, Inc."
In general, anyone who deals with shoppers data through the credit card processing flow should adhere to the PCI standards. There are different levels of compliance- relating to the different the different players involved in the transaction.
You need to make sure your merchant account provider is compliant (ask for a
certificate!) , If not, look for another one ( you can find few here
CreditCardProcessing-r-us.com) and try to learn from him if you are subject to any compliance requirements (DSS?).
Dan Pirogovsky
Co founder and SVP BD
CreditCardProcessing-r-us.com