All the major card companies banded together and formed a standards group: https://www.pcisecuritystandards.org/security_standards/pci_dss.shtml https://www.pc

All the major card companies banded together and formed a standards group: https://www.pcisecuritystandards.org/security_standards/pci_dss.shtml https://www.pcisecuritystandards.org/security_standards/pci_... Once you reach a certain volume of transactions you are required to comply. Doing so now is probably not feasible if you're small, but you can still take the spirit of the standard and do your best.