Istanbulkart. Buy it from a yellow Biletmatik machine at any metro, tram or ferry stop, including both airports, or from a kiosk with the logo. The card itself costs around 165 lira, is not refundable, and comes empty; load lira at the same machine. One anonymous card serves up to five people, so a family needs one card and a bigger balance. A ride costs around 40 lira, a little more on the ferries.
Take the ferry. The Şehir Hatları boats from Eminönü or Karaköy to Kadıköy and Üsküdar are public transport on the Istanbulkart, run every 20 minutes or so and cross the Bosphorus for the price of a tram, which makes the paid cruise optional.
Mosques and the five prayers. Every working mosque is free and closes to visitors for about half an hour before and after each of the five daily prayers; on Friday the midday prayer keeps tourists out until around 2:30 p.m. Shoulders and knees covered, a headscarf for women (lent at the door), shoes off into the bag provided. Sultanahmet and Süleymaniye cost nothing.
Hagia Sophia. Since January 15, 2024 foreign visitors pay €25 and follow a one-way route through the upper gallery, entered from a separate gate, while the main floor stays a prayer hall. Visitor hours run about 9 a.m. to 7:30 p.m. and pause for prayers, longest on Friday from about 12:30 to 2:30 p.m. Children under 8 enter free.
Topkapı and the pass. From 2026 Topkapı sells one combined ticket, around ₺2,750 (about €55), that includes the Harem and Hagia Irene; the palace closes Tuesday. The Museum Pass Istanbul costs around €145 for a few days and skips the Topkapı line, but it does not include Hagia Sophia and the Harem has moved in and out of it, so add up your museums before buying.
Bazaars, tax and the lira. The bazaar opens Monday to Saturday, about 8:30 a.m. to 7 p.m., closed Sunday and the first days of the Bayram holidays; the Spice Bazaar opens Sunday. Hotels add a 2 percent accommodation tax to the bill. The lira moves fast, which is why museums price in euros: pay by card where you can, always in lira when the terminal offers a choice, and draw cash from a bank branch’s machine rather than a street ATM, which charges heavily. Keep small bills for tea, taxis and the bazaar.
On the day. Check prayer times in the morning and place the mosques between them; Waystop’s hours check will flag Hagia Sophia set for Friday lunchtime. Load the Istanbulkart once for the whole day, carry the headscarf in your bag, and keep the €25 Hagia Sophia receipt on its stop in Documents.