Your Card on Amex Pay is protected by your Secure Device Lock (password, pattern, PIN or fingerprint). For your security, when you make a contactless purchase using Amex Pay, you must verify with your chosen Secure Device Lock method. All QR code based transactions are necessarily authenticated using your Card PIN. A Device Card Number, separate and unique from your physical Card Account number, is used to make purchases with Amex Pay. All of your payment information will be stored securely on your device and your physical Card details are never shown in the app or shared with the merchant when you make payments.