Istanbul eSIM — plans from ₹299.00

Istanbul splits its arrivals between two very distant airports, and getting that wrong is expensive. Istanbul Airport (IST) lies north-west on the European side and is linked to the city by the M11 metro towards Gayrettepe and by Havaist coaches; Sabiha Gokcen (SAW) sits on the Asian side, served by the M4 metro. Crossing between them can take well over two hours, so the app you open on landing genuinely matters. Turkish tourist SIMs are sold at both airports, but registration is passport-based and the device-registration rules around foreign handsets make it a more involved purchase than travellers expect. An eSIM avoids all of it: install it at home on Wi-Fi, leave it off, and it registers when your phone first finds a Turkish network after landing, with validity starting at that connection. From the kerb you can then order a licensed taxi through BiTaksi or iTaksi, both of which are the local norm, or check which metro line actually reaches your hotel.

Turkcell, Vodafone and Turk Telekom cover Istanbul densely, and the eSIM attaches to whichever partner network is strongest rather than a single one. LTE is the workhorse across both continents and is fast in Sultanahmet, Beyoglu, Kadikoy and along the Bosphorus shore. Underground, Istanbul is better than most: the metro lines and the Marmaray tunnel under the strait carry signal, so the crossing between Europe and Asia does not black out. Ferries across the Bosphorus and out to the Princes' Islands stay connected for most of the route, weakening near Buyukada. Inland day trips to Bursa and the Black Sea villages are covered on main roads, thinning in the forested hills. See the Turkiye plan or Europe.

Download offline maps for both sides of the Bosphorus, and specifically for Sultanahmet's tangle of lanes and the hills of Beyoglu, where navigation regularly puts you on a staircase. Keep data live for ferry timetables, museum passes held on the phone, taxi apps and translation, which is genuinely useful in the Grand Bazaar. Café and hotel Wi-Fi is common and often needs a phone number to sign in, which is another argument for having your own connection. Battery drains fast on ferry-and-walk days with the screen bright in the sun, so carry a power bank. Hotspot works on most plans. If you are heading on, see Cappadocia and check your handset on the devices page.