Any tax office should do. I went to the office called “Beyoglu Maliye Beyoğlu Vergi Dairesi" – this is located in Mesrutiyet street near the Tunel Square. When you are in the office say “"Vergi Kimlik Numarasi"
What to bring: i) Passport ii) Copy of picture/essential info page and entry visa page in the passport
Cost: Free
