This is not a debit, but a reservation. To make sure you can pay for your trip, we reserve at the start of the rental an amount on the card that varies depending on the partner (for city bikes from nextbike and ÖBB Bike, for example, currently €20). When we receive the invoice for the rental, the actual amount will be charged. If the invoice amount is higher, a subsequent booking will be made using the same payment method. If the actual amount is lower, the difference will be released again.