You will need to get an electronic VISA for Turkey prior to arrival in Istanbul. You may purchase it at https://www.evisa.gov.tr/en/

Important notes for the visa application:

• We suggest to apply as a TOURIST and NOT to mention that you are attending a conference.
• Enter an arrival date a few days BEFORE your ticketed or planned arrival and to enter a departure date from Turkey a few days AFTER you plan to leave; this allows for some changes that may come up without having to apply for a new visa.
• You will need to pay the US$20.00 fee with your credit card.
• Each traveler requires his/her own application, so if you are bringing your partner or guests along, the partner or guests will need their own visas.