For enhanced security, your actual debit card number will never be stored on the phone or exposed to the merchant. Your debit card number will instead be replaced by a unique digital number (i.e. Device Card Number, visible on the left side of the card in the Samsung Pay screen, and in the main app when viewing your registered DBS Debit Card) each time you add a new card to your device. This Device Card Number will then be transmitted to merchants in place of your actual card number for purchases.