How to use Istanbul transport card (Istanbulkart): top-up limit, cost, and sharing between passengers

In August 2026 a participant shared his habit: top up the Istanbulkart and change money as needed rather than in one big amount — in the morning, once the day's plan is known. In his words, even if you overshoot a little, the card with its balance stays valid for 3 years after the last transaction. For the maths, he shared a link to the current transport fares.

In June 2026 a traveler planned a route in a maps app from Sabiha Gökçen airport to the center: the metro was fastest, and the fare with a transfer was shown as 42 and 75 lira per person. These are app figures from June 2026; Istanbul fares change, so check them before you travel.

Whether two people can travel on one card came up in June–July 2026. Participants work on the basis that two people can use one card, but the partial refunds on transfers are credited as for a single card; one traveler explicitly calculated a trip for two on one card as 'without transfer discounts'. If saving money matters, a card each works out better.

In June 2026 a traveler mentioned a 2,750-lira top-up ceiling on the card: she wrote that she was close to that limit and asked how to tell how much more she could add. To avoid hitting the ceiling and leaving spare money on the card, another participant in August 2026 advised topping up in small amounts to match the day's plans.