The credit card is required so that the guest can pay online. The use of smart check-in / out is only possible by entering a credit card. The credit card data is stored and encrypted in full compliance with PCI DSS (Payment Card Industry Data Security Standard).
The guest no longer has to carry a physical credit card with him and the card does not have to be handed over to the hotel upon arrival. For guests without credit card details, payment via Smarthotel is not possible. These guests must settle their bill independently.