SIM cards, wifi and paying by card in Istanbul: a setup guide

The tourist SIM, and the rule nobody mentions

A tourist package from Turkcell, Vodafone or Turk Telekom costs roughly 20 to 30 euro for 20 to 50 GB over thirty days, and you need your passport at the counter. The rule that catches people: a foreign phone used with a Turkish SIM is blocked after 120 days unless you register the handset and pay a substantial tax. For a one-week trip that never bites, but do not lend the SIM to someone staying on.

Why an eSIM is usually the better answer

For five to ten days, an international eSIM bought before you fly costs a few euro for the data you will actually use, activates in the taxi, needs no passport and no counter, and roams onto the same Turkish networks. It also avoids the handset-registration clock entirely, because the connection is roaming rather than a domestic line. Check your phone supports eSIM before you rely on this.

Cards, cash and the lira

Contactless works everywhere in Sisli, Nisantasi and any restaurant with a menu. Cash is for the bazaar, small cafes, some taxis and tips. At an ATM always decline the machine's offer to convert to your own currency. That conversion costs three to seven per cent. Change money at a doviz office in the city, never at the airport, and never with someone on the street.

How treatment payments should work

You should be able to pay by bank transfer in euro before arrival or by card at the clinic, against an itemised invoice with the facility's name on it, a card surcharge, if any, is disclosed in advance. What should never happen is cash handed to an individual, a transfer to a personal account, or a price that changes on the day of surgery. Those three are the warning signs.

The Ones People Actually Ask.