The city has an integrated electronic ticket system which uses smart RFID cards called İstanbulKart. It’s a contactless smart card used at public transport in the city and can be acquired at major transport interchanges. The main benefit of İstanbulKart is to save time and money while travelling. The easy to use and easy to obtain reasonably priced İstanbulKart may be used in any public transportation throughout the city eith the benefit of cheaper rates compared to buying a ticket or token. Also, the card can be loaded at special machines or some kiosques which can be found almost in every main bus stations and ferry stations.
For more information: http://www.iett.gov.tr/en/main/pages/transportation-cards/147