Postal services in Turkey are operated by PTT (Turkish Republic Post Telephone Telegraph Administration General Directorate). You can find the closest PTT office by using the maps in this website. PTT offers the fallowing services: local and international postal services, transfers, foreign exchange, sales of credits for GSM and call cards for pay phones available on the streets, American Express cheque transactions, prepaid telephone services, sales of TCDD (Turkish State Railways).
If you want to send parcels to other countries, the PTT office in the Büyük Postane (Grand Post Office ) in Sirkeci. As the officers have to see what is inside the parce before sending, you had better leave it open not to waste time. Express Mail Service is more expensive. Don’t use this service for sending your valuables. The international cargo companies can be useful as well, but they are more expensive than PTT.
Some PTT Center in Istanbul
Beyazıt: Mithatpaşa Avenue, İbrahimpaşa Street, No:19
Kapalı Çarşı (Grand Bazaar): Beyazıt Mahallesi, Gani Çelebi Street, No:1, Kapalıçarşı.
Sirkeci (Büyük Postane – Grand Post Office): Hobyar mahallesi, Büyük Postane Avenue, No:25
Karaköy: Arap Camii Mahallesi Kürekçiler Avenue
Taksim: İstiklal Street, Galatasaray Square