Do you need cash in Istanbul, or can you pay by foreign bank card everywhere?

If opening or maintaining a new card costs more than the fees you expect to pay on one trip, setting up a separate account may not be worthwhile. Compare the one-off card cost with your likely Istanbul transaction fees before applying.

Do not rely solely on card payments at markets, on TurYol ferries, or for some hotel extras such as laundry: cash may be required.

Paying cash may qualify you for a hammam discount. For Istanbul, it is sensible to keep roughly a quarter of your overall budget in cash even if you plan to pay for most expenses with a Visa card.