The Card Identification # is the 4 digit, non-embossed
number printed above your account number on the
face of your
card. This number is recorded as an additional security precaution.
Private Payment User? Please use the CID from your
issued American Express Card.
If your AMEX account number does not have a plastic card
associated with it, then you do not have a Card Identification
#. In this case, you should enter the last 4 digits of your AMEX
account number in the Card Identification # field in order for your
transaction to be processed.