Why use an eSIM in Turkey?
Istanbul is the only city where your phone changes continents on a metro ride, from the European side to the Asian side through the Marmaray tunnel under the Bosphorus, and it is a good test of your data. Türkiye has a rule that catches visitors out: a phone brought from abroad can use a Turkish SIM from Turkcell, Vodafone or Türk Telekom for a limited period before its IMEI must be registered and a hefty fee paid, and every local SIM is tied to your passport at the counter. Tourists rarely hit the deadline, but the paperwork is real.
A travel eSIM for Türkiye roams onto the Turkish networks rather than joining them, so the IMEI rule does not apply, there is no counter at Istanbul Airport (IST) or Antalya (AYT), and your home SIM stays in for calls and OTPs with roaming data off. Whether you came for the Grand Bazaar, a Cappadocia balloon or the Turquoise Coast, BiTaksi, Google Maps, the İstanbulkart app and WhatsApp with your guide all run on data paid for before you left.

