No. To book a double room, a single HotelCard is sufficient. All specified room categories (i.e. also multi-person and family rooms) can be booked with only one card. Accordingly, the prices listed on our portal are always per room and night (not per person).
Conversely: If you wish to book two rooms in the same period, you must present two HotelCards or two HotelCard holders must each present one HotelCard.
Please also note that the HotelCard is personal and therefore non-transferable. You must present the HotelCard in physical or digital form together with your ID at check-in in order to benefit from the HotelCard discount.