The so-called 'Anonim Kart', the anonymous card is best suited for tourists. The card can be recharged over and over again and used indefinitely, while the disposable cards are limited in the number of trips. The disposable cards do not pay off financially if you stay a few days in İstanbul and want to take the bus, metro, or ferry more often. The anonymous İstanbulkart can be used by several people at the same time. So you can buy one card and share it with your family/friends. Just make sure that you have enough credit on the card. The one-time cards can also be used by several people at the same time. So it is always enough if you buy only one card regardless of the number of travelers.