Question related to credit card file (VCF format)

Hi all,

This might be a basic question for some and I would really appreiate a quick reply.

My client is implementing Credit Card Clearing and has decided upon recieving a VCF format file. My client is also PCI complaint, so can not store credit card information in the system. My question at this time is that without the credit card information, what do we use as an identifier to map the file information to SAP

I would like to get some feedback from people who faced a similar situation and what were the solutions?

Thanks in advance.